• Don't overlook our Welcome Package, it contains many links to important and helpful information about functions at VHT like posting pictures and sending PMs (private messages), as well as finding the parts you need.

    AD

1971 CL450 that sat for 40 years.

Danager4792

Veteran Member
Joined
Sep 13, 2023
Total Posts
472
Total likes
256
Location
Memphis, TN
1971 CL450-K4 w/ 5,098 miles.

Backstory: In 1983, an 85 year old man dropped his bike off at a motorcycle shop in Michigan. Shortly after, he passed away. The family had no interest in keeping the motorcycle, or paying the shop fees, so they gave them the title. It sat in the corner for 40 years. New ownership took over this shop recently, and decided to sell it. The next owner was a man 45 mins from me in TN. Due to his wife developing an illness, he only made it to buying new spark plugs, and a battery(that is too large for the frame). The bike came with a box of spare parts(pictured below). There were zero records about why the bike came in the first place, or what the shop had done to it 40 years ago.
C3668DC5-3B44-4FAD-BEF6-C8978418891D.png
6C65D293-F16C-4B80-A855-15D1355ACD94.jpeg
AFABF1A5-36C7-4EF7-B9AF-674BFBF8FDC6.jpeg
9D14EE70-B5C5-4B62-ADA8-EBE7CAA724F9.png
6D8678FC-410D-4E1C-BEFE-39EA2D6477A7.jpeg

1st I checked compression. Cold engine, with marvel mystery oil, 140psi both sides. He then poured gas into the cylinders and the bike did fire up for about 2-3 seconds.

Getting it home I started to notice things, such as the right air filter and case missing, Honda emblems with broken pins, mismatched colors on mirrors, very torn seat, and black crankcase covers.

My goal: Get the bike back running mechanically sound (fuel, air, spark, engine tuning) and worry about cosmetics later. I do not have much experience mechanically, but this will be my first bike to learn on. The bike will most likely be sent to my mechanic friend to do the brakes, suspension, and tires. And any advanced engine tuning. I would also like to piece together what happened to this bike before, and after being at the shop. To figure out it’s story.

This is what I’ve done so far:

I cleaned out probably 90%-95% of the fuel tank rust, and got a new gas cap since the old one was loose and the o-ring was dry rotted.
CCE3C02D-F5A2-4827-AB0F-D00B1C4F20DF.jpeg
D65A88C6-409C-44E0-9726-8A78466CDB83.jpeg
B2949CCD-59AC-4E36-9799-80BA8EA25BA8.jpeg
Next I pulled both of the carbs, they were very nasty on the side. I disassembled them, ran the carb bodies through an ultrasonic cleaner, then installed all new internals. The floats had ancient gas in them, so I replaced those too. For the rest of the fuel system, I also bought a new petcock valve, and new 5.5mm fuel line.

57028F33-9B2D-4F2E-9239-F8A6974903C6.jpeg
906AC1AE-50EC-43B0-8403-E23DFE5DEE08.jpeg
3DF39BF1-8498-495F-A4C0-4A8B6F6D5C9A.jpeg

Next, I cleaned the oil filter, then changed the oil. While doing this, I also installed all new o-rings, even for the dipstick and drain plug. I noticed the right crankcase gasket looked terrible, so I changed that out too. I went with SAE 10w-40 oil, seeing that’s what the dipstick cap says. But after searching this forum, I will be switching over to Rotella T4 15w-40 conventional with the added zinc. Upon cleaning the drain plug and filter, I did notice shiny metal glitter and debris.

DD8DF7E7-07C0-4168-98E1-4577FC9A87C8.jpeg
A9B17DFF-25FE-4E61-8350-19CA3EAAD46A.jpeg
2D452E9D-FE1A-4A01-9428-E01205DD290E.jpeg
D79ECF72-1FCB-41DB-B452-0C94DA40166A.jpeg
Currently typing up 2nd post
 
DBD1A8B3-D35B-43D2-B506-DC0638E9E8C3.jpeg

New intake manifolds w/ cleaned gasket surface
C80E6E1C-7EE8-4D3C-908D-864C4404A7FE.jpeg
60119AB0-49B6-44D4-9F91-C2A2AA02FC22.jpeg

New air filters(black plastic housing, and new rubber joint seals are on the way)
B65C9FEF-6BF8-4F87-BFAA-6497D578EB3E.jpeg
Next was the big day of my 1st start attempt (yesterday Sept 22nd). Spark was good. I installed the rebuilt carbs, clean fuel tank, new petcock valve, new fuel lines, new air filters, and checked the oil level. My heart was pounding when I reached for the starter button!


I was so shocked and overwhelmed that I didn’t even consider to check the RPMs. I had probably put 2-4 hrs worth of work every night into this bike for two weeks, and it finally started. It was idling at 3000rpm. I ran it for about 45 seconds.


Upon cranking it again, I immediately tinkered with the idle screw on both carbs and got it down to roughly 1200-1400rpm. I also noticed some white smoke from the back of the exhaust and the front side of the engine where the exhaust pipes come out. There was also a fairly aggressive oil leak underneath.


Current progress as of today (Sept 23rd)

I took the left engine cover off to replace the leaking gasket. I also took some pictures of the exhaust.

F1AA88AA-381F-4A8B-8F4C-47006F60FD36.jpeg
3ED2F706-85EE-4EAB-AA82-CB6088C71819.jpeg
97AB1246-8B54-4A78-8B2C-7B597C086136.jpeg
4D69D0B0-8A48-4203-A528-B66DABE75DCC.jpeg
6CC861D8-C2A1-404E-AC5D-3541BC881907.jpeg
9FDD3615-3762-496C-BC72-F6E38174DEBC.jpeg
7632215E-A246-4E6A-ADDF-D2B369D86DAB.jpeg
4B07906F-0510-4E74-A2BD-8D6C9AC1DBE1.jpeg

New gasket is in
84752963-C79E-409D-BAA3-4B351E930D1A.jpeg

How the bike is sitting now
1487F43D-B7B4-407A-9A77-B0B3923EDEAF.jpeg

Hope these pics do justice for any help and assistance.. Thank you everyone
 
Nice efforts so far, and good pics to work with which makes visible a lot of stuff. Some stuff that I wish I had seen before doing some of the things you did.

I'm sure you realize that the gross amount of sealer on both crankcase covers was a bad idea, and I hope you didn't do that when you replaced both gaskets. I didn't see any with the right crankcase cover gasket, that's a really good thing because the oil pump and pump output is there and it flows through that cover, so it's the quickest way to get loose sealer goo into the passages up the right 2 cylinder studs to the top end.

Now to some of the stuff I see, and at least one thing that means you may have to take the left crankcase cover back off again at some point in the future if the grommet around the alternator wiring starts leaking. I'm sure you noticed how hard the rubber of that grommet is. Though the use of any sealer (except very judiciously in specific areas) is not a good idea in these engines, that is one place you need to use it in this situation because the grommets aren't available (in fact, they were never sold separately). The hard grommet will allow some seepage around it if no sealer is used. Also, you should never shortcut removing the left crankcase cover without also removing the front sprocket cover since the alternator wiring is old and brittle and you can cause yourself future grief without realizing it. Yes, I know the video by A Motorcycle Nut shows him doing it, but he'a a backyard hack who shortcuts a lot of the stuff he shows in videos, which is why we hate videos for doing proper repairs.

Another point is the position of the clamps on the carbs. Good that you replaced the intake manifolds, but you should position the clamps directly over the back of the rubber manifolds right where the carb is clamped or the clamp will not properly tighten the rubber to the grooved area on the carb body that fits into the rubber. Same with the clamps on the air cleaner hoses, though I know you have slight fitment issues to adjust to with the length.

I suspected the muffler had a rust hole in it based on the loudness I heard in the first video, but that's just how they are after decades of sitting. Almost impossible to find one in good condition these days and the rest of yours is in decent shape, you're way ahead of many who find these bikes in serviceable condition.

The idle seems to be "hunting" a bit so I wonder if the carbs are completely clean, or if it's sloppy advancer springs and timing off a bit. Before you do cam chain, valves and points/timing, let's discuss those things.

Now an observation which may be obvious to you as well - this engine has been apart despite the low miles. There are telltale signs all over it, starter cable not behind the starter motor as it was when new (common shortcut), gaskets not original on every area of the engine visible in the picsw, and non-OEM bolts in some places related to the engine mounting areas. I wonder if that shop did more than just rob a few parts off it while it sat there for years, maybe even swap engines with another one they had in for service. Just a thought and it really doesn't matter, but these bikes tell lots of stories to those who are used to seeing how they really came from the factory when new. In fact, it's the exact same bike I bought new in my senior year of high school, so I'm very familiar.
 
I'm sure you realize that the gross amount of sealer on both crankcase covers was a bad idea, and I hope you didn't do that when you replaced both gaskets. I didn't see any with the right crankcase cover gasket, that's a really good thing because the oil pump and pump output is there and it flows through that cover, so it's the quickest way to get loose sealer goo into the passages up the right 2 cylinder studs to the top end.

I cleaned up the “goo” and stuck gasket pieces on the metal with a little bit of wd40 and green scotchbrite. Then wiped it as dry as possible with a shop towel. Something about all that sealer didn’t make sense to me either.
Now to some of the stuff I see, and at least one thing that means you may have to take the left crankcase cover back off again at some point in the future if the grommet around the alternator wiring starts leaking. I'm sure you noticed how hard the rubber of that grommet is. Though the use of any sealer (except very judiciously in specific areas) is not a good idea in these engines, that is one place you need to use it in this situation because the grommets aren't available (in fact, they were never sold separately). The hard grommet will allow some seepage around it if no sealer is used.

What’s the most common sealer that I could use? I may have something in my tool shed. This is one of those things that’s new to me.

I suspected the muffler had a rust hole in it based on the loudness I heard in the first video, but that's just how they are after decades of sitting. Almost impossible to find one in good condition these days and the rest of yours is in decent shape, you're way ahead of many who find these bikes in serviceable condition.

Do you think that hole is going to effect engine performance? Should I look in the future about getting it welded? Or is there anything else I can do to restore it. Also, I do have a set of brand new copper exhaust seals. I’m thinking that will slightly help the white smoke I saw from that area.

Now an observation which may be obvious to you as well - this engine has been apart despite the low miles. There are telltale signs all over it, starter cable not behind the starter motor as it was when new (common shortcut), gaskets not original on every area of the engine visible in the picsw, and non-OEM bolts in some places related to the engine mounting areas. I wonder if that shop did more than just rob a few parts off it while it sat there for years, maybe even swap engines with another one they had in for service. Just a thought and it really doesn't matter, but these bikes tell lots of stories to those who are used to seeing how they really came from the factory when new. In fact, it's the exact same bike I bought new in my senior year of high school, so I'm very familiar.

Yeah I must admit, the engine does look pretty sloppy as far as screws and gaskets are concerned. The screws are on their last leg, most of them look stripped so I am being extra careful.

The idle seems to be "hunting" a bit so I wonder if the carbs are completely clean, or if it's sloppy advancer springs and timing off a bit. Before you do cam chain, valves and points/timing, let's discuss those things.
Whatever you suggest I do, for the carbs, advancer springs and timing, I am all over it!
 
I cleaned up the “goo” and stuck gasket pieces on the metal with a little bit of wd40 and green scotchbrite. Then wiped it as dry as possible with a shop towel. Something about all that sealer didn’t make sense to me either.
Some suggest a little grease to hold the gasket in place, but if you put the gasket on the crankcase instead of the cover the dowels will mostly hold the gasket still. I've never thought putting anything petroleum-based on dry gaskets, seems silly to soak some oil-based stuff into a gasket you want to seal oil in.

What’s the most common sealer that I could use? I may have something in my tool shed. This is one of those things that’s new to me.
Many will dislike my opinion about using silicone sealer because they paint the concern with a broad brush, and understandably so for some users, but when used sparingly and not in the wrong places it is very reliable to seal areas that can, and have been known to be in my experience, problematic. I hate seeping head gaskets.
Do you think that hole is going to effect engine performance? Should I look in the future about getting it welded? Or is there anything else I can do to restore it. Also, I do have a set of brand new copper exhaust seals. I’m thinking that will slightly help the white smoke I saw from that area.
Can't say it will help your 'white' smoke, but before you replace the exhaust gaskets make sure there isn't more than one pair in there, it's easy to not notice them when they're crushed and exhaust blackened. The leaks at the muffler won't affect the performance enough for you to notice. If the metal isn't too thin and rusty, and not weakened by it, a welder might be able to put a metal repair cover over the area but the seam areas will be more difficult.
Whatever you suggest I do, for the carbs, advancer springs and timing, I am all over it!
When you're ready to do the tune-up items post some pictures of the points and plate so we can see what shape those parts are in, and we'll go over the cam chain and valve adjustment process. If you have ANY questions or aren't sure of anything, don't go ahead before saying something. These bikes require patience in some cases and we've had people get in a hurry and try something before they're sure, and sometimes it ends badly.
 
Can't say it will help your 'white' smoke, but before you replace the exhaust gaskets make sure there isn't more than one pair in there, it's easy to not notice them when they're crushed and exhaust blackened. The leaks at the muffler won't affect the performance enough for you to notice. If the metal isn't too thin and rusty, and not weakened by it, a welder might be able to put a metal repair cover over the area but the seam areas will be more difficult.
9D2E238B-5D97-4266-A3C6-9F833FF7E4F4.jpeg
Thanks for the heads up. They were really camoflauged in there.

When you're ready to do the tune-up items post some pictures of the points and plate so we can see what shape those parts are in, and we'll go over the cam chain and valve adjustment process. If you have ANY questions or aren't sure of anything, don't go ahead before saying something. These bikes require patience in some cases and we've had people get in a hurry and try something before they're sure, and sometimes it ends badly.

DE64342D-8A3E-4D52-AB5B-972F39F0CEA0.jpeg
88F53006-AD33-4E75-BCD8-C9F3572FFCCB.jpeg
I barely tried to move those weights that are connected to the springs. They move freely with ease.
 
When you grab the breaker cam lobe (that opens the points) and rotate it, the weights will open and when you release the cam lobe they should return immediately with no resistance. Check that the springs have no slack when the weights are fully returned, and that the springs immediately begin to stretch as the breaker cam moves the weights. If there's any slack in this movement at all it can lead to a hanging idle, dropping down slowly after you rev it.

As to the cold start routine to allow oil flow to the top end fully, try to keep the engine at idle speed for at least the first full minute. I wait a full 2 minutes at idle before riding as shown in this early section of one of my videos.
 
When you grab the breaker cam lobe (that opens the points) and rotate it, the weights will open and when you release the cam lobe they should return immediately with no resistance. Check that the springs have no slack when the weights are fully returned, and that the springs immediately begin to stretch as the breaker cam moves the weights. If there's any slack in this movement at all it can lead to a hanging idle, dropping down slowly after you rev it.

As to the cold start routine to allow oil flow to the top end fully, try to keep the engine at idle speed for at least the first full minute. I wait a full 2 minutes at idle before riding as shown in this early section of one of my videos.
I just tested everything you mentioned, and they pass all of the tests. Just to be sure, here’s a video.

 
When you grab the breaker cam lobe (that opens the points) and rotate it, the weights will open and when you release the cam lobe they should return immediately with no resistance. Check that the springs have no slack when the weights are fully returned, and that the springs immediately begin to stretch as the breaker cam moves the weights. If there's any slack in this movement at all it can lead to a hanging idle, dropping down slowly after you rev it.

As to the cold start routine to allow oil flow to the top end fully, try to keep the engine at idle speed for at least the first full minute. I wait a full 2 minutes at idle before riding as shown in this early section of one of my videos.
I actually missed one of your tests. When the weights are seated and I move them outwards, they are a bit weak.

 
Yeah, you'll need to pull the springs out to do it. Just tightening up the curve and then trimming the excess off the end so it's easier to re-install.
Roger that. Hopefully this solves the hanging idle. If not, it will be one item scratched off the list.
 
I actually missed one of your tests. When the weights are seated and I move them outwards, they are a bit weak.

The simplest test is to grab the breaker cam lobe and very gently turn it to see what portion of movement is not accompanied by the springs reacting to the weights moving. There should be zero movement without a reaction from the springs.
 
Roger that. Hopefully this solves the hanging idle. If not, it will be one item scratched off the list.
Ignition timing is part of that equation too. If the timing is retarded AND the advancer springs are sloppy, you can fix the advancer springs but you may still have a slow float down to idle speed. Engines 'like' to be advanced at lower rpm when the timing is retarded a bit, and when the rpms get above idle and the advancer corrects the retarded timing it often 'wants' to stay that way.
 
Ignition timing is part of that equation too. If the timing is retarded AND the advancer springs are sloppy, you can fix the advancer springs but you may still have a slow float down to idle speed. Engines 'like' to be advanced at lower rpm when the timing is retarded a bit, and when the rpms get above idle and the advancer corrects the retarded timing it often 'wants' to stay that way.
I will tackle those advancer springs tomorrow. What’s next after that?

Edit: I only ask so I can get a heads up on reading.
 
Last edited:
I've been incredibly busy with forum functions lately so forgive me if you already mentioned it, but have you checked the cam chain, valves and timing yet? If not, those are next. And when you're ready to do them, you need to approach the valve adjustment correctly and on this bike it isn't like any others except, to an extent, the 350. So let me know when you're ready to do that and we'll go over doing it properly.
 
I've been incredibly busy with forum functions lately so forgive me if you already mentioned it, but have you checked the cam chain, valves and timing yet? If not, those are next. And when you're ready to do them, you need to approach the valve adjustment correctly and on this bike it isn't like any others except, to an extent, the 350. So let me know when you're ready to do that and we'll go over doing it properly.
Is it because the eccentric rocker pins or is there something else?
 
Is it because the eccentric rocker pins or is there something else?
The eccentric shafts are definitely unusual for those who've never worked with them, but mostly because of the cam lobe to follower arrangement, and because of separate cams as well. It obviously isn't rocket science, but it always amazes me why it seems more difficult and complicated to those who aren't familiar. New owners always need to understand the oiling weaknesses, the damage that can happen from that problem which will negatively affect valve adjustment, and even getting the crankshaft on the right stroke to do the adjustment correctly as with all the twins.
 
I've been incredibly busy with forum functions lately so forgive me if you already mentioned it, but have you checked the cam chain, valves and timing yet? If not, those are next. And when you're ready to do them, you need to approach the valve adjustment correctly and on this bike it isn't like any others except, to an extent, the 350. So let me know when you're ready to do that and we'll go over doing it properly.
It’s all good. The info here has been priceless. I will most likely be doing the cam chain/valve adjustments in the next day or two.

Most things I have done so far for this bike have been straight forward. I would like a lot of information and wisdom, because these jobs seem like they don’t have much room for error. Also, I am a strong visual learner, the FSM does not really provide much imagery. But I’ll be following along with that. I am not going to follow any YouTube Motorcycle Hipster Science either. I am gonna erase any memory I have of watching those videos a month ago. So a couple questions to start off with.

Finding the compression stroke.

With thumb over spark plug hole, and turning the engine counter-clockwise(never turn clockwise), wait until you feel air pressure on your thumb. Is it at that moment you have entered the compression stroke? And the next travel in the turn is in the compression stroke?

Cam chain adjustment:

Do I make this adjustment on the LT mark like the FSM says? Or will I be making the adjustment 90 degrees past the LT mark?
 
It’s all good. The info here has been priceless. I will most likely be doing the cam chain/valve adjustments in the next day or two.

Most things I have done so far for this bike have been straight forward. I would like a lot of information and wisdom, because these jobs seem like they don’t have much room for error. Also, I am a strong visual learner, the FSM does not really provide much imagery. But I’ll be following along with that. I am not going to follow any YouTube Motorcycle Hipster Science either. I am gonna erase any memory I have of watching those videos a month ago. So a couple questions to start off with.

Finding the compression stroke.

With thumb over spark plug hole, and turning the engine counter-clockwise(never turn clockwise), wait until you feel air pressure on your thumb. Is it at that moment you have entered the compression stroke? And the next travel in the turn is in the compression stroke?

Cam chain adjustment:

Do I make this adjustment on the LT mark like the FSM says? Or will I be making the adjustment 90 degrees past the LT mark?

I'm in the middle of something important right now, let me get back to this with you in an hour or two.
 
Finding the compression stroke.

With thumb over spark plug hole, and turning the engine counter-clockwise(never turn clockwise), wait until you feel air pressure on your thumb. Is it at that moment you have entered the compression stroke? And the next travel in the turn is in the compression stroke?
While that is one way to do it, you'll find that it's simple when you actually begin because you will have removed the valve covers and will have visual access to the movement of the valvetrain. You will have to loosen the clamps on the carbs (and in the process, relocate for better clamping results) and pull the carbs out of the manifolds to make room to remove the intake valve cover, the exhaust valve cover is easier though the horn can get in the way. A word of caution here as well - you have to be careful with the valve cover bolts, they are 6mm threads so smaller than a 1/4" SAE bolt, and they are easy to strip in the head if you overtighten. From the look of a couple bolts in your intake valve cover above (one allen head and one that looks suspiciously like a 1/4") the PO or the cannibalizing shop may have already caused you some grief. You'll need new gaskets for this operation as well.

Once the valve covers are off (and the 3 screw alternator cover so you can turn the crankshaft with a 14mm wrench), you can watch the intake valve open on the left cylinder, then close as you rotate, and once the intake valve closes you look for LT on the rotor. THEN you are at LTDC on compression stroke, no guessing. Same for the right cylinder, stopping at T after seeing the right intake valve close. Then you're ready to adjust the valves on the cylinder you're working on once at TDC for that cylinder. More on that once you are ready to do the work, valve covers off and gaskets in hand.

Cam chain adjustment:

Do I make this adjustment on the LT mark like the FSM says? Or will I be making the adjustment 90 degrees past the LT mark?

I have never tried the cam chain adjustment according to the FSM, the problem being that the cam chain tension is directly affected by a cam lobe starting to open a valve. The cam lobe can push backward against the camshaft and cause reverse tension on the chain and if that lobe is opening an intake valve, it can create false tension on the intake side of the chain where the tensioner roller is and overcome the strength of the spring on the tensioner, effectively eliminating it adding any tension and worst case scenario, actually pushing the tensioner push bar backwards causing the chain to be looser instead of tighter. I do the cam chain adjustment first, once both valve covers are off, so I can watch the exhaust side of the cam chain when an exhaust valve is being opened, which pulls the cam chain tight on the exhaust side, and then look at the intake side of the chain to see the tension there. I hold tension on the crankshaft's rotation while the exhaust valve is being opened and loosen first the lock nut, then the lock bolt on the tensioner to allow it to tension the intake side where it's located, then lock the tensioner by tightening the bolt and then the lock nut.
 
The simplest test is to grab the breaker cam lobe and very gently turn it to see what portion of movement is not accompanied by the springs reacting to the weights moving. There should be zero movement without a reaction from the springs.
I got the advanced springs adjusted, to where there is movement now when turning the breaker cam lobe. Unfortunately, I was clumsy and snapped an e-clip. I’ll be headed to a few hardware stores to find a match.

03E73A85-35C0-4522-A6A8-14DD32D48C1F.jpeg
 
While that is one way to do it, you'll find that it's simple when you actually begin because you will have removed the valve covers and will have visual access to the movement of the valvetrain. You will have to loosen the clamps on the carbs (and in the process, relocate for better clamping results) and pull the carbs out of the manifolds to make room to remove the intake valve cover, the exhaust valve cover is easier though the horn can get in the way. A word of caution here as well - you have to be careful with the valve cover bolts, they are 6mm threads so smaller than a 1/4" SAE bolt, and they are easy to strip in the head if you overtighten. From the look of a couple bolts in your intake valve cover above (one allen head and one that looks suspiciously like a 1/4") the PO or the cannibalizing shop may have already caused you some grief. You'll need new gaskets for this operation as well.

Once the valve covers are off (and the 3 screw alternator cover so you can turn the crankshaft with a 14mm wrench), you can watch the intake valve open on the left cylinder, then close as you rotate, and once the intake valve closes you look for LT on the rotor. THEN you are at LTDC on compression stroke, no guessing. Same for the right cylinder, stopping at T after seeing the right intake valve close. Then you're ready to adjust the valves on the cylinder you're working on once at TDC for that cylinder. More on that once you are ready to do the work, valve covers off and gaskets in hand.



I have never tried the cam chain adjustment according to the FSM, the problem being that the cam chain tension is directly affected by a cam lobe starting to open a valve. The cam lobe can push backward against the camshaft and cause reverse tension on the chain and if that lobe is opening an intake valve, it can create false tension on the intake side of the chain where the tensioner roller is and overcome the strength of the spring on the tensioner, effectively eliminating it adding any tension and worst case scenario, actually pushing the tensioner push bar backwards causing the chain to be looser instead of tighter. I do the cam chain adjustment first, once both valve covers are off, so I can watch the exhaust side of the cam chain when an exhaust valve is being opened, which pulls the cam chain tight on the exhaust side, and then look at the intake side of the chain to see the tension there. I hold tension on the crankshaft's rotation while the exhaust valve is being opened and loosen first the lock nut, then the lock bolt on the tensioner to allow it to tension the intake side where it's located, then lock the tensioner by tightening the bolt and then the lock nut.
Thank you for this information. I am going to be giving it a few more reads before I prepare for the job. I’ll be having more questions, and posting pictures of the engine internals, before I start.
 
When you grab the breaker cam lobe (that opens the points) and rotate it, the weights will open and when you release the cam lobe they should return immediately with no resistance. Check that the springs have no slack when the weights are fully returned, and that the springs immediately begin to stretch as the breaker cam moves the weights. If there's any slack in this movement at all it can lead to a hanging idle, dropping down slowly after you rev it.

As to the cold start routine to allow oil flow to the top end fully, try to keep the engine at idle speed for at least the first full minute. I wait a full 2 minutes at idle before riding as shown in this early section of one of my videos.

Update:

I stretched the advancer springs a hair, and put in new e-clips that are snug and reinstalled the advancer assembly and points plate. Upon firing the bike up, I didn’t have time to see if the idle changed any, because I heard this very loud squeak noise. Turned the bike off shortly after. The bike has made this noise before, but this time it was more frequent. Imagine a basketball players shoe on a basketball court, but x10. A very quick sharp noise.

Also, I noticed another oil leak. The screw below the points cover.

 
Any idea where the squeak is coming from? In the video from the first start I feel like I heard some strange sounds underneath that high idle. Weird engine sounds give me the creeps.

How does it feel when you turn the motor over slowly by hand? Does the squeak occur when you use the kickstart? You could try with the ignition off to avoid running the motor and possibly causing damage due to the source of this noise.
 
Last edited:
Any idea where the squeak is coming from? In the video from the first start I feel like I heard some strange sounds underneath that high idle. Weird engine sounds give me the creeps.

How does it feel when you turn the motor over slowly by hand? Does the squeak occur when you use the kickstart? You could try with the ignition off to avoid running the motor and possibly causing damage due the the source of this noise.
It’s definitely the most audible on the left side of the bike, towards the back of the engine. Around the carbs and intake manifolds. I’m currently suspecting it’s sharp high pressure air making it’s way out of the intake boots/manifolds. But this is just 5 mins of me listening.

With ignition off, and using the kick starter, I do hear a slight squeak, but it’s about 90% quieter near where the kickstarter is. A little puzzled now. Haha
 
Any idea where the squeak is coming from? In the video from the first start I feel like I heard some strange sounds underneath that high idle. Weird engine sounds give me the creeps.

How does it feel when you turn the motor over slowly by hand? Does the squeak occur when you use the kickstart? You could try with the ignition off to avoid running the motor and possibly causing damage due to the source of this noise.
After thinking some more:

The loud squeak of air could be coming from the exhaust.

The bike is currently idling at 800-1000rpm after trying to adjust the screws on the carbs(first time ever doing this) to get that fluctuating 1500-2000rpm down. Messed with air/fuel mixture screw, and idle screw on both sides. It could very well be too lean right now, with too much air(this is a guess, I just started learning about carbs.)

The RPM is low enough right now that the bike does shut off. It will let out a loud air “squeak” when it does. Or if you try to feather the throttle to keep the RPM’s above 900, it will squeak.

I was planning on working on the valve adjustment/cam chain next. Then doing the points. And finally learning how to tune the carbs. I was probably jumping ahead too far when I started adjusting screws on the carbs. That will be a whole other lesson to learn about
 
Last edited:
I hesitate to ask you to reproduce the squeak sound, but it sounds like it's occurred several times already. It would be helpful to hear it through a video, in order to better assess its origin. It's hard for me to imagine a loud squeak of air coming from the motor under normal conditions.

There is a setup guide for the carburetors on the dohc 450's created by the late Bill Lane. I believe it's called Bill Lane's Setup Guide or something similar. You might request that document from the VHT Library and start reading to prepare for the carb setup. Feel free to ask questions.

I believe you already have the FSM to read up on the valve adjustment and timing, correct?
 
There are 2 typical possibilities for that squeaking sound. We've seen leaking carb manifolds make that sound when the gasket isn't sealed completely (or the tabs have been overtightened and the sealing surface is arched in the middle, but yours are new), or it could be the starter clutch. The design of the starter clutch can create a small squeaking noise when the engine comes to a stop under compression on one cylinder and as it quits turning, kicks backward just slightly causing the starter clutch parts to chatter slightly. However, if the squeaking noise is more than just a short moment as the engine comes to a stop when shut off, it's likely something else like a leaking manifold gasket. Other than the cam bearing covers being bushing surfaces, the rest of the engine is ball and roller bearings which almost never make any noises or they're usually shot.
 
I hesitate to ask you to reproduce the squeak sound, but it sounds like it's occurred several times already. It would be helpful to hear it through a video, in order to better assess its origin. It's hard for me to imagine a loud squeak of air coming from the motor under normal conditions.

There is a setup guide for the carburetors on the dohc 450's created by the late Bill Lane. I believe it's called Bill Lane's Setup Guide or something similar. You might request that document from the VHT Library and start reading to prepare for the carb setup. Feel free to ask questions.

I believe you already have the FSM to read up on the valve adjustment and timing, correct?
I will be posting a video later for sure. Then I’ll be taking off the carbs and intake manifolds, to try and readjust the gaskets. I most likely overtightened them as AD suggested.

Yes I have access to the FSM, I’ll be posting more pictures and have more questions, before I get started on valves/cam chain.
 
Upon trying to recreate the air squeak, I fired the bike up for maybe 5 seconds and couldn’t get it to come back on after that. I put hands on both exhaust pipes and the right one was cold. So, I’m thinking the right cylinder is not firing now.
 
I guess it didn't sound like any kind of metallic gnashing of teeth or anything like that? May as well proceed cautiously with your tune-up.

I think you mentioned valves on the agenda. That will give us a peek at your cams if you can capture a couple of photos with the covers off.
 
I guess it didn't sound like any kind of metallic gnashing of teeth or anything like that? May as well proceed cautiously with your tune-up.

I think you mentioned valves on the agenda. That will give us a peek at your cams if you can capture a couple of photos with the covers off.
I’m also suspect that the right cylinder wasn’t firing up yesterday either. And I just didn’t notice. The sound I’m about 99% sure was high pressure through rubber. I just checked the right side and it has spark.

I have always had a problem getting fuel to flow properly through the right carb fuel line. It’s always had air in it. I pulled the line off to test the petcock, and fuel came running out of the line. Does this mean a clogged carb?


Edit: Right side is still showing 140psi compression

BFB2AD4F-1D35-4F87-9EF7-F3B7F71FAED5.jpeg
 
Last edited:
I have always had a problem getting fuel to flow properly through the right carb fuel line. It’s always had air in it. I pulled the line off to test the petcock, and fuel came running out of the line. Does this mean a clogged carb?
Easy test. Close petcock. Remove the fuel line from the petcock, but leave connected to the carb body. Remove float bowl. Hold a cup under the carb and spray carb cleaner into the fuel line to see if it makes it through the float valve into your cup.

Alternatively, you can empty the float bowl and check to see if it fills back up after 5-10 seconds of the petcock being open.

I use black Honda 5.5mm fuel line, which means I don't see the air bubbles in the lines. I had a translucent blue type before and saw them even when things were working fine.

There is also a vent in the carb body that allows fuel entering the bowl to displace air from the carb body. I'm not suspicious of that at this point, but thought it is worth mentioning.
 
Easy test. Close petcock. Remove the fuel line from the petcock, but leave connected to the carb body. Remove float bowl. Hold a cup under the carb and spray carb cleaner into the fuel line to see if it makes it through the float valve into your cup.

Alternatively, you can empty the float bowl and check to see if it fills back up after 5-10 seconds of the petcock being open.

I use black Honda 5.5mm fuel line, which means I don't see the air bubbles in the lines. I had a translucent blue type before and saw them even when things were working fine.

There is also a vent in the carb body that allows fuel entering the bowl to displace air from the carb body. I'm not suspicious of that at this point, but thought it is worth mentioning.
I appreciate that info. I’ll definitely be trying that soon.

Update: I’m now thinking the problem is going to be electrical. So after visibly seeing the fuel line fill up more to the right carb.. I hit the starter for about 2 seconds and saw faint smoke coming from the battery/wires/terminals followed by a very loud pop from the same area around the battery that caused a leaf to blow from under the bike.. The negative lead felt warm. yeah im not gonna be trying to start this bike anymore. Here’s the wiring/cables if anyone sees anything out of whack..


Edit: may have been a pop from the exhaust, there’s a rusted hole in the bottom of it that could have blown the leaf.. anyways.. I think it’s time to get started on valves/cam chain/points
3A532C67-BC5C-48C2-8136-F908382A7B2D.jpeg
31D29876-D3CE-4614-8EE3-7EFAD370CB8F.jpeg
 
Last edited:
The short heavy wire with the red band should be bolted down to the + battery terminal along with the end of the yellow wire bolted to it. Granted, that yellow wire is not original and appears to have been added when switching from a single glass fuse to a blade fuse. That white wire is also an add-on and appears completely superfluous — maybe it was for a battery tender??

As ballbearian pointed out, any of those wires off battery + could cause problems when making contact with any part of the frame, including the metal underside of the seat. Notice the short wire to the starter solenoid does not go through the 15A fuse, so it'll just cook anything grounded that it touches.

I see you have the original selenium rectifier — that red wafer looking thing behind the battery. You'll probably want to upgrade to a modern rectifier + regulator combo unit and Sparck Moto is a trusted source around here, although there are other sources.
 
I wouldn't be surprised , by looking at this, that here may be some (poor quality?) repairs to the wiring in this area. All fixable, if you get a diagram from the FSM. You do have that, right? All the grounds need to be cleaned and checked. Not sure how that fuse is wired in either. It should be from the batt+ to the key switch (black wire?). The stock rectifier relies on it's(rusty) mount bolt to ground it.
Take your time and learn what's what and do it right to avoid future plagues. Your ignition system will do better too. A new Sparckmoto reg/rec is good preventive measure, but needs to be hooked up right and with a separate ground.
Post a pic of your wiring diagram so we can do Q&A intelligently.
 
That's a mess that needs to be cleaned up, almost none of it is original. I'll try to find a picture of the correct arrangement, it isn't that often we see one so blatantly re-worked in such a poor way. Yes Ballbearian, the gifts of the PO. Which usually suck.
 
Here are some pics of what things should look like, though you should be removing the separate rectifier (orange finned device) and regulator (regulator is under the battery box attached to the bottom of it, 3 wires coming off it) to replace both components with a single rectifier/regulator combo unit from Sparck Moto because he sells the best unit for the best price and gives the best service (and he's a longtime VHT member, Sonreir) - http://www.sparckmoto.com/Products/Detail/7


450 battery wiring.png

450 solenoid conections.png
 
Wow. Thanks guys. I didn’t realize I was sitting on top of a hack-man special with the battery wiring. It always looked off to me, should have posted it sooner. Electrical is a weakness to me but I’m gonna pay attention and get it understood.

Question#1: Is this skinny black wire supposed to be the ground that screws onto the frame of the battery box?

B74BCF50-9F23-4720-82A1-8BE4F2793E40.jpeg


#2: Would there be any logical reason to swap out the main wiring harness for a solution to this? I’m assuming y’all are suggesting the most simple and efficient fix.

#3: Before AD helped me discover more ways to shop around for parts, I did order a Rectifier/Regulator from CMC. If there would be any advantage over getting the SparkMoto, I’ll do that.

#4: Do I need to flip my gold battery terminals around any?

Thanks
 
AD: The green wire on the battery negative terminal in the picture above would be coming from the modern rec/reg, correct?
Assumedly, but the 450 harness also has a small gauge green ground wire. It's typically connected to a frame bolt nearby, like one of the 6mm bolts for the older seat latch or the metal mount for the rear gas tank rubber strap where I have mine connected. Since the large gauge ground for the starter goes to a motor mount bolt it ties the frame into the ground circuit just fine when all connection points are clean.
 
Wow. Thanks guys. I didn’t realize I was sitting on top of a hack-man special with the battery wiring. It always looked off to me, should have posted it sooner. Electrical is a weakness to me but I’m gonna pay attention and get it understood.

No offense, but when you look at that mess did you really think that was factory? I mean, that's some pathetic stuff right there and Honda would never have done it.
Question#1: Is this skinny black wire supposed to be the ground that screws onto the frame of the battery box?

Black, IF a factory wire (but it doesn't look factory) is NOT a ground wire, on Hondas of that era black is switched 12v. Since we do not know from the picture whether or not it's tied to 12v then it needs to be determined first, and cleaned up or replaced because that terminal on the end is not good.
#2: Would there be any logical reason to swap out the main wiring harness for a solution to this? I’m assuming y’all are suggesting the most simple and efficient fix.

Not necessarily, but better pictures of all the wiring in the area will help us know more. PICTURES period, you can never post enough when you need to know more about something. Words can't fully describe that kind of thing.
#3: Before AD helped me discover more ways to shop around for parts, I did order a Rectifier/Regulator from CMC. If there would be any advantage over getting the SparkMoto, I’ll do that.

Probably no advantage, the only difference is how much money that's gone from your wallet for a similar functioning part.
#4: Do I need to flip my gold battery terminals around any?

No, the polarity is currently correct for the locations of the components you want to connect as closely as possible to factory. The small wires from the solenoid (black, yellow w/ red) go to their respective connections in the harness, they feed the solenoid power (black) and starter button signal (ground) from the right handlebar switch.
 
Wow. Thanks guys. I didn’t realize I was sitting on top of a hack-man special with the battery wiring. It always looked off to me, should have posted it sooner. Electrical is a weakness to me but I’m gonna pay attention and get it understood.

Question#1: Is this skinny black wire supposed to be the ground that screws onto the frame of the battery box?




#2: Would there be any logical reason to swap out the main wiring harness for a solution to this? I’m assuming y’all are suggesting the most simple and efficient fix.

#3: Before AD helped me discover more ways to shop around for parts, I did order a Rectifier/Regulator from CMC. If there would be any advantage over getting the SparkMoto, I’ll do that.

#4: Do I need to flip my gold battery terminals around any?

Thanks
#1 (even before #1) Get your battery out of there, you're nowhere near ready to hook it up. That black may or may not be original. You need to check if anything has been cut out or added to the original wiring. This is assessing your original harness for repair or replacement.
#2 See #1. I've seen many cause more problems and confusion with a swap AND it has to be the correct replacement harness (they are not cheap)
#3 Cancel if you can and get a Sparck but if paid already don't worry it'll work, WHEN you are ready for that.
#4 No

#5 GET THE CORRECT WIRING DIAGRAM for your model and year..... ask ancient dad

You can do this. Diagrams were written/drawn for this purpose. Kinda like The Bible.
 
No offense, but when you look at that mess did you really think that was factory? I mean, that's some pathetic stuff right there and Honda would never have done it.
I knew it wasn’t factory, I just didn’t know the severity of it. I assumed the only modification was that white wire connected to the big orange positive wire to “extend” it, to fit a bigger battery. Thanks for all of the help/clarity.

Tonight I’ll take the battery out, and take more pics of the wiring. And if it doesn’t need to be done in a later step, I’ll go ahead and install the rectifier/regulator combo.
 
I knew it wasn’t factory, I just didn’t know the severity of it. I assumed the only modification was that white wire connected to the big orange positive wire to “extend” it, to fit a bigger battery. Thanks for all of the help/clarity.

Tonight I’ll take the battery out, and take more pics of the wiring. And if it doesn’t need to be done in a later step, I’ll go ahead and install the rectifier/regulator combo.
You have the correct battery. Just verify all the wiring or fix any hacks to make it to spec. It may not be all that bad but do it right ,or it's wrong. You need to check the diagram even to put in the new rec/reg unit (colors may not be the same). Get a bullet connector kit and crimper too, so you can keep the stock connectors and not cut the original harness unnecessarily.
 
Back
Top Bottom