1971 CL450 that sat for 40 years.

[Danager4792]

I have seen Jim say this twice recently but have been led to believe by numerous posts over the last decade that dried up felts on the throttle shafts can contribute to high idle issues on original carbs. I have certainly pulled dried up, crumbly felts from some old carbs. So is this really not an issue and is instead a long perpetuated myth?
Personally I have found my own replacement solution for the old felts and routinely replace them when rebuilding carbs. I feel I have had more reliable results overall since doing so. Maybe I have just gotten better and more thorough rebuilding carbs as time has moved along, I dunno? I would agree that attempting to replace them requires careful work and attention to details (like orienting the plate bevels and use of correct driver and loc-tite on tiny JIS screws) so one must be diligent with their work on this. But speaking generally of complete carb rebuilds, it is truly unnecessary and a complete waste of time to replace the felt material?
In the context of Danager4792 and his troubles I would agree that adding a drop or two of oil to the throttle shafts where they enter each carb would not hurt and would be a simple and easy way to eliminate dried up felts from his list of possible problems so he could continue moving forward. Perhaps this was Jim’s point all along, if so forgive me, but I was also interested in some clarification of this long held belief for myself.

I suppose tonight I could accurately spray the throttle shafts to see if there is a change in idle. I think that would give us enough evidence to determine if it’s a myth or not.

Steve had mentioned the felt seals over the phone, for me to check them. I had brought it up to him previously. I suppose at that point I was just grasping at straws to figure out anything that could be wrong. I personally think using the strobe light to check dynamic timing will give me way more evidence/results than a few drops of oil on those seals.

 

[LongDistanceRider]

I have seen Jim say this twice recently but have been led to believe by numerous posts over the last decade that dried up felts on the throttle shafts can contribute to high idle issues on original carbs. I have certainly pulled dried up, crumbly felts from some old carbs. So is this really not an issue and is instead a long perpetuated myth?
Personally I have found my own replacement solution for the old felts and routinely replace them when rebuilding carbs. I feel I have had more reliable results overall since doing so. Maybe I have just gotten better and more thorough rebuilding carbs as time has moved along, I dunno? I would agree that attempting to replace them requires careful work and attention to details (like orienting the plate bevels and use of correct driver and loc-tite on tiny JIS screws) so one must be diligent with their work on this. But speaking generally of complete carb rebuilds, it is truly unnecessary and a complete waste of time to replace the felt material?
In the context of Danager4792 and his troubles I would agree that adding a drop or two of oil to the throttle shafts where they enter each carb would not hurt and would be a simple and easy way to eliminate dried up felts from his list of possible problems so he could continue moving forward. Perhaps this was Jim’s point all along, if so forgive me, but I was also interested in some clarification of this long held belief for myself.

Felt, even oiled, will not seal vacuum. If the replacement of felts solves a vacuum leak it will be a temporary fix as when felt dries out the leak will return. The real cause of the problem in this case would be a worn throttle shaft, unlikely, or shaft bore, probable.
Attention to detail with any carb is important. No boogered screws when done, everything snugged and tightened correctly, linkages aligned, etc.
I do replace the felts as needed when doing carbs. At least 50% are remnants or missing.

 

[LongDistanceRider]

I suppose tonight I could accurately spray the throttle shafts to see if there is a change in idle. I think that would give us enough evidence to determine if it’s a myth or not.

Steve had mentioned the felt seals over the phone, for me to check them. I had brought it up to him previously. I suppose at that point I was just grasping at straws to figure out anything that could be wrong. I personally think using the strobe light to check dynamic timing will give me way more evidence/results than a few drops of oil on those seals.

Rather than spraying the shaft area use a syringe and drop some gasoline on the shaft, couple of drops.
When you use a spray the air for a few feet around becomes enrichened so the results are skewed. Worse if you're using a fan to keep the engine cool.

 

[ballbearian]

Thanks for the heads up, I have seen people use an extra stator cover with a hole cut in it. Hopefully I won’t have to spend too much time with this procedure

You can even duct tape a paper plate with a hole in it. I just use a 1' board under the stand and cardboard on the floor.

I use a strobe on my little 6volt bikes too, with a separate 12volt battery for light power.

 

[Danager4792]

Update:

I purchased the harbor freight strobe light and performed a test. I am very happy with what I discovered.. It’s bad news, but good news in the sense that I am now finding evidence of what is wrong.

Note: It took me a long time to get the idle at a safe rpm for the engine, my goal was to get it decent enough to use the strobe light.

Previously, it was always the right cylinder staying just barely warm and not wanting to heat up. Yesterday, while working on the bike with my dad, the right cylinder decided to be the dominant one, in the sense of being the “hottest”.

Tonight, it went back to previous ways, the left cylinder was firing strong, with the right cylinder being the colder one. Anyways, onto the results.

Left cylinder: Strobe light immediately came on, and was not intermittent. The results showed the left cylinder firing perfectly, staying directly on the LF mark.

Right cylinder: Strobe light did not come on. I removed the spark plug boot and barely stuck it on, then the strobe light came on. Was not intermittent either. I took a look at the timing marks and it is not timed correctly. It is nearly impossible to capture what I saw with the light, so I moved the crankshaft to the position that I saw.



It was hovering near that T mark. Clearly away from the “F” mark.

Here’s a short video for the right cylinder

https://imgur.com/a/NbskiYm

Y’all are the experts here but I’m thinking I’ll need to revisit the points. (Possibly new ones, if they don’t pass the gap measurement). Adjust or replace the new boots/caps, I may have not screwed them in far enough. Thanks again..

 

[ancientdad]

Y’all are the experts here but I’m thinking I’ll need to revisit the points. (Possibly new ones, if they don’t pass the gap measurement). Adjust or replace the new boots/caps, I may have not screwed them in far enough. Thanks again..

Points are adjustable and until the fiber rubbing block wears enough that you can't get the gap large enough to be within spec, they don't typically wear out. The contacts on the points can get pitted from the constant low level arcing when they open, but with a good set of condensers that takes a long time. You'll have to refresh my memory so I don't have to go back through dozens of pages, but if you didn't replace the coils then did you snip about a 1/4" off the ends of the plug wires and then screw the caps back on them again for a fresh connection? You can screw the caps on multiple turns, you'll feel them getting snug on the wire end when you've gotten them 'tightened' in enough. When I see the wire and plug cap relationship as you pull the cap off the right plug, it looks like the wire is not fully in the cap (but it's hard to be sure from the video). Notice how the right cylinder makes occasional thumping noises after the cap is only part way on the plug? The gap the spark is jumping to reach the plug end is helping the plug fire under compression, which usually means that plug is a bit fouled. This is probably contributing to your idle problem since it's likely only idling on one cylinder when you make all your adjustments and then when the other cylinder fires the idle speed changes dramatically. You'll never get the carbs right until the ignition is worked out properly. Retarded timing on the right cylinder and/or a plug that is compromised and not firing consistently has to be addressed before you bother with any carb adjustments.

 

[Danager4792]

Points are adjustable and until the fiber rubbing block wears enough that you can't get the gap large enough to be within spec, they don't typically wear out. The contacts on the points can get pitted from the constant low level arcing when they open, but with a good set of condensers that takes a long time. You'll have to refresh my memory so I don't have to go back through dozens of pages, but if you didn't replace the coils then did you snip about a 1/4" off the ends of the plug wires and then screw the caps back on them again for a fresh connection? You can screw the caps on multiple turns, you'll feel them getting snug on the wire end when you've gotten them 'tightened' in enough. When I see the wire and plug cap relationship as you pull the cap off the right plug, it looks like the wire is not fully in the cap (but it's hard to be sure from the video). Notice how the right cylinder makes occasional thumping noises after the cap is only part way on the plug? The gap the spark is jumping to reach the plug end is helping the plug fire under compression, which usually means that plug is a bit fouled. This is probably contributing to your idle problem since it's likely only idling on one cylinder when you make all your adjustments and then when the other cylinder fires the idle speed changes dramatically. You'll never get the carbs right until the ignition is worked out properly. Retarded timing on the right cylinder and/or a plug that is compromised and not firing consistently has to be addressed before you bother with any carb adjustments.

Thanks a lot for the reply.

The spark plugs, wires, caps, condensers, and coils are all brand new. The caps are ‘resistor’, and the spark plugs are ‘non-resistor’. I can try tightening the caps a little more to see if i establish better connection.

It is very much possible that’s the plugs are fouled. They were black and wet the last time I checked them. Is it possible to clean a fouled plug or should you get a new ones?

What’s the best way to go about adjusting retarded timing on the right cylinder? Will it involve dynamic timing and moving the entire points plate? Or static timing and individually adjusting the right point?

 

[ancientdad]

Thanks a lot for the reply.

The spark plugs, wires, caps, condensers, and coils are all brand new. The caps are ‘resistor’, and the spark plugs are ‘non-resistor’. I can try tightening the caps a little more to see if establish I better connection.

Try snugging them up, but the reason it seemed like the cap wasn't all the way on is likely because the wires are new and soft so they bend more easily near the cap entry point.

It is very much possible that’s the plugs are fouled. They were black and wet the last time I checked them. Is it possible to clean a fouled plug or should you get a new ones?

Since B8ES are NLA, replacing the right plug with another non-resistor plug is a lot more difficult (if you're using BR8ES then you're using a resistor plug already, with double the resistance because you have resistor caps)

What’s the best way to go about adjusting retarded timing on the right cylinder? Will it involve dynamic timing and moving the entire points plate? Or static timing and individually adjusting the right point?

I'm not sure I typed this already in this thread, but in case I did not here it is:

The proper method involves turning the engine until the advancer breaker cam opens the left set of points to the fully open position and setting the gap of that set of points at .014", then turning the engine until the right set of points is fully open and setting them at .014", then adjust the left side timing by rotating the points plate so the left points break at LF. You then lock the points plate and check the timing on the right cylinder to see if the points break at the F mark and if they do not, you adjust the gap to get the right points to break at F.

If after that adjustment is made, the gap on the right points is less than .012", you go back to the beginning and reduce the left points gap to .012", set that timing by rotating the plate to open at LF, then check the right side again and adjust the right points to open at F.

Note that if the points plate has a sloppy fit in the base, it can allow the points gap to change when rotating the plate.

Yes, it can take a few tries to get both correct, but that is the procedure since there is only one plate that both sets of points are mounted on, so when you rotate the plate to advance or retard the left timing it affects both.

 

[Danager4792]

Try snugging them up, but the reason it seemed like the cap wasn't all the way on is likely because the wires are new and soft so they bend more easily near the cap entry point.

Since B8ES are NLA, replacing the right plug with another non-resistor plug is a lot more difficult (if you're using BR8ES then you're using a resistor plug already, with double the resistance because you have resistor caps)

I'm not sure I typed this already in this thread, but in case I did not here it is:

The proper method involves turning the engine until the advancer breaker cam opens the left set of points to the fully open position and setting the gap of that set of points at .014", then turning the engine until the right set of points is fully open and setting them at .014", then adjust the left side timing by rotating the points plate so the left points break at LF. You then lock the points plate and check the timing on the right cylinder to see if the points break at the F mark and if they do not, you adjust the gap to get the right points to break at F.

If after that adjustment is made, the gap on the right points is less than .012", you go back to the beginning and reduce the left points gap to .012", set that timing by rotating the plate to open at LF, then check the right side again and adjust the right points to open at F.

Note that if the points plate has a sloppy fit in the base, it can allow the points gap to change when rotating the plate.

Yes, it can take a few tries to get both correct, but that is the procedure since there is only one plate that both sets of points are mounted on, so when you rotate the plate to advance or retard the left timing it affects both.

I was actually lucky enough to snag 4 x B8ES plugs off of eBay. Two are in the bike right now, so I have a spare set.

The next day I get about 1-2 hours of spare time, I’ll start with the plug caps and get them more snug. Then I’ll take my time to get the points correct. If I run into any troubles or problems I’ll be sure to ask

 

[ancientdad]

I was actually lucky enough to snag 4 x B8ES plugs off of eBay. Two are in the bike right now, so I have a spare set.

The next day I get about 1-2 hours of spare time, I’ll start with the plug caps and get them more snug. Then I’ll take my time to get the points correct. If I run into any troubles or problems I’ll be sure to ask

I meant to mention, sometimes you can spray the fouled plug with carb spray generously down into the insulator area below the electrodes and it will clean up enough to run normally, depends on how fouled it was.

 

[12ozPBR]

Lots of times I just use a small brass or stainless wire brush to clean up carbon fouled plugs. Do what you can to extend the life of those B8ES plugs since they are now hard to come by.

 

[ballbearian]

The copper strands of the spark plug wires need to be around the screw tip of the cap. I'll take a small pick and spread them so the course thread of the cap screw makes good contact up the middle of those strands. They get chewed up after a few removals so you need to trim off a quarter inch or so to get fresh copper strands.
Some of the caps have a slotted brass connection piece (with the little spring wire clip) that grabs the threaded tip of the spark plug. Make sure it's not loose and the spring clip is grabbing the plug tip. That may have been why you got it to fire when you pulled back on it a bit. If you can't fix it then a new cap is needed.

 

[ancientdad]

The copper strands of the spark plug wires need to be around the screw tip of the cap. I'll take a small pick and spread them so the course thread of the cap screw makes good contact up the middle of those strands. They get chewed up after a few removals so you need to trim off a quarter inch or so to get fresh copper strands.
Some of the caps have a slotted brass connection piece (with the little spring wire clip) that grabs the threaded tip of the spark plug. Make sure it's not loose and the spring clip is grabbing the plug tip. That may have been why you got it to fire when you pulled back on it a bit. If you can't fix it then a new cap is needed.

He mentioned that the coils, caps, condensers and plugs are new.

 

[Danager4792]

Thanks for all of the advice everyone.

In other good news, I just picked up my seat pan from Steel Rose Metal Co in Memphis. It’s a one man show. He specializes in metal fabrication and his passion is hot-rodding and restoring 1950’s trucks and muscle cars. He teaches welding classes on the weekends.

Before:




After: (This is a close-up of the rusted area). He also painted it without me knowing, so that was a bonus to see!





I told him it was going on a ‘71 CL450, he said “thats funny, I have a ‘71 CB350” while he was pointing up at the ceiling.



He said he got it for basically nothing, it was found in a shed. He’s never had time to restore it, so it’s wall art for the time being.

With his permission I took a picture of the shop.


He is about to start a YouTube channel about his work, and asked to record our interaction and talk about the bike, but I politely declined and said I am not Hollywood worthy lol.

 

[ancientdad]

Nice job, interesting shop and obligatory shop dog. I love shops like that, there are always great stories to hear about past and current projects. Hilarious seeing that 350 hanging, at first glance it made me think I'd have to rotate the pic. My machinist's shop looks a lot like that, just more lathes and mills around. No matter how big your garage is, you always need more space.

 

[Danager4792]

Nice job, interesting shop and obligatory shop dog. I love shops like that, there are always great stories to hear about past and current projects. Hilarious seeing that 350 hanging, at first glance it made me think I'd have to rotate the pic. My machinist's shop looks a lot like that, just more lathes and mills around. No matter how big your garage is, you always need more space.

He had interesting “welder’s art” everywhere. He made a stand for his angle grinder out of an old pipe and a 1920’s wheel at the base.

I mentioned that when he decides to bring his CB350 down from hanging like a bat, that I would direct him to this website.

I showed him pictures of the hole in the exhaust on my CL450, and he said he’d work on that and take care of it. I definitely see that happening sometime in the future

 

[ballbearian]

Nice work on that seat.

 

[12ozPBR]

His work on the seat looks great! Thanks for posting the pics of his cool shop. Love that kind of stuff!

 

[Danager4792]

I will be starting on the process of adjusting the points, and right cylinder spark plug & cap this weekend. Thanks again everyone for the input about the issues. I’ll also have another special update about the seat pan tomorrow!

In the meantime, I do have a few questions about the front fender.

Will I be able to fit a period correct CL450 front fender on this bike? Also, what years would work?

To my knowledge, the front end consists of:
(Please correct if wrong)

-CB Front Fender w/ black ‘support bar’
-CB750 top bridge
-Internal fork springs
-Forks from a CL450K5/500T/CB750
-Fork dust shields from a 500T

Compatibility options have created a bit of confusion in my head.

I’d be willing to guess that the gap between the fender and worn front tire isn’t even a 1/2 inch. It’s very tight. It was explained by Steve that CB fenders went on ‘18in wheels, not ‘19in.

My goal is to have chrome front & rear fenders.

Question #2: If I were to acquire fenders off of eBay, is it fairly simple to clean spotted rust off of chrome? Thanks again..

I have seen CL450K5 front fenders for sale and just wanted to be sure before I buy.

(I have a lot in the works for the front end. Period correct rubber gaiters, cable stays, new tires, wheel bearings, rebuilt drum brakes, etc..)

‘71 CL450K4

 

[ancientdad]

Unfortunately, a CL fender is not going to fit the forks currently on your bike properly. Note the angled bolt holes for the fender mounts on the lower fork legs, as opposed to the bolt holes in the CL K4/K5 fender.

 

[Danager4792]

Update on the seat:

I just picked it up from ‘Got Ya Covered Upholstery’ in Memphis, TN. Retired Navy vet who works out of a shop at his house. I dropped off the original tore up foam and leather so that he would have an example to work from. Also dropped off new chrome buttons. He was not very excited to create an exact OEM copy, cause that ruins his creative flow. LOL. So we went over different variations of stitching and color combinations. I chose triple stitching between the padded squares with a thread color “Dark Willow” to accent the squares.

Before:

https://imgur.com/a/U392yIG

https://imgur.com/a/09iiHQf

After:

https://imgur.com/a/adZfIOd

https://imgur.com/a/cbNehlo

He sent me about 3 videos talking about his process along the way. Figured it may or may not help someone, worth a shot. I’ll be posting those soon.

 

[ancientdad]

Looks like nice work.

 

[LongDistanceRider]

Nice. Unless you're doing restoration or resto-mod the seat doesn't have to be exact, in fact some of the originals were pretty bad new. Like slick smooth seat surface so you slide around.

 

[Danager4792]

Here are the videos that were sent to me through the process, plus a couple more pics:

https://imgur.com/a/jixloOC

https://imgur.com/a/zdsvcyb

https://imgur.com/a/HcwvWoY

https://imgur.com/a/xFHtaEw

https://imgur.com/a/dQ3bhGg

 

[Cycleranger]

That seat looks great! Nice videos of the reconstruction.
Where did you get the new buttons? I need some of those.

 

[ballbearian]

That seat looks great! Nice videos of the reconstruction.
Where did you get the new buttons? I need some of those.

I just saw some .

Reproduction Chrome Seat Cover Buttons - Honda CL350 CB400F CB450K

Reproduction chrome seat buttons that fit many of the Honda seats that came stock with chrome seat buttons. These are universal so they can fit many different makes and models.

4into1.com

 

[ballbearian]

Glad you were able to talk the artist into an original style redo. Really looks nice.

 

[Danager4792]

That seat looks great! Nice videos of the reconstruction.
Where did you get the new buttons? I need some of those.

Ballbearian posted the exact ones that I ordered. The upholsterer said they were quite difficult to bend on the other side, the “prongs” on the end are pretty heavy duty.

 

[Danager4792]

Glad you were able to talk the artist into an original style redo. Really looks nice.

There are a couple of Harley bike groups that he has made custom seats and jackets for. He said he’s used to someone dropping off a seat and saying “go crazy man!”.

 

[Cycleranger]

I just saw some .

Reproduction Chrome Seat Cover Buttons - Honda CL350 CB400F CB450K

Reproduction chrome seat buttons that fit many of the Honda seats that came stock with chrome seat buttons. These are universal so they can fit many different makes and models.

4into1.com

Dammit, I just ordered some stuff from them yesterday! I didn't see those.

 

[Danager4792]

Greetings gentlemen, I'm here with another update.

I was able to track down the right cylinder firing issues with a timing light. Very thankful for ballbearian's recommendation of purchasing one.
The right spark plug turned out to be very carbon fouled when I pulled it. Pitch black and dry. I cleaned it with carb cleaner and a towel. The right cylinder is firing now with the spark plug boot seated fully on the plug.
I think it got fouled in the midst of trying to tune the carbs with bad mixture settings. Also, at one point during tuning the carbs, I noticed "exhaust smoke" shooting out of the right cylinder spark plug hole. I was guilty of not tightening the plug down all of the way. Another 1/8th of a turn tightened it correctly. I never want to strip anything on the aluminum engine, so maybe I was a bit overly cautious there.

Next, I got on the phone with Steve and he walked me through the entire points timing setup. This was due to the timing on the right cylinder firing a little late. I ended up installing the Japan manufactured points plate from CMC. I accidentally stripped the screw threading for the right point on the original plate about an hour before I phoned him. I was very upset about that because I was aware of how shallow the threading was. But, in the midst of things, the new points plate gave me new points, felt, and wires. I also lighlty sanded the contacts to get rid of whatever material was on there. When I was done I used the recommended PJ1 Chain Lube for the felt. I wasnt sure how much to apply, I'll provide a picture to verify.

Concern#1: I did have to shift the points plate far to the right(clockwise) to set the left point. Is it normal for it to have to shift that far?



After verifying precise timing marks on both L & LF with the strobe light, I decided to start tuning the carbs.

When adjusting the idle screws there is a lot of "afterfire" from the exhaust pipes when I get the bike to 1200rpm. The pipes towards the rear give off a "gurgling" sound. Revving the engine sounds pretty bad. The bike will idle fine at 800rpm, but of course that isn't at spec.
I currently have the fuel mixture screws at 3/4 turn out. If I adjust them to a 1/2 turn, the pipes get very hot and there is white smoke. Too lean. When I adjust it to 1 full turn out, the engine seems to sputter, maybe too rich. So I've been keeping it at 3/4 turn.

The carbs:

I noticed that when I have the idle screws all of the way backed out, the left carb idle screw is a lot higher from the arm than the right one is. I’ll have to readjust the left throttle plate to let it be more “closed” than the right one. Not sure why I was ok with that the first time around when adjusting the throttle plates.

Concern#2: Before I redo the carbs, (cleaning and adjustments), I want to be sure that my exhaust isn’t causing any air leaks to affect the idle. Also, whenever I’ve picked up the exhaust after removing it, I can hear rattling on the inside. I’ve highlighted below where I can feel air come out with the engine running.

 

[ancientdad]

All those holes (obviously from rust) are small leaks and will have little to no effect on anything. You should know that those screws and 'bolts' screwed into the top of the muffler were put there by someone trying to close rust holes for exhaust leakage (first picture shows a hex bolt, likely a hex-headed sheet metal screw, and a slotted screw, neither of which are OEM), they did not come in the muffler from the factory. All internal parts of that muffler were spot-welded and no screw or bolts were used to hold the muffler together, only external bolts were used for the mounts to the bike.

A few drops of chain lube on the felt will last a long time, you went a little bit excessive on the rubbing blocks for the points but it will be fine. Just wipe off the excess, the intent is to minimize the use so it doesn't sling around in the points cover and potentially get into the points gaps and dirty the contacts.

 

[Danager4792]

Anyone have any idea why my brake lamp bracket has two holes for bolts on the top of it?

I’ve looked up CL450 brake lamp housings and don’t see those holes anywhere. Don’t see it on the parts diagram either.

It’s one of those things that wouldn’t matter if I got an answer or not, I just notice it every now and then and wonder

*Old picture from my phone.

 

[ancientdad]

Definitely not original and it wasn't noticed because of the black color of the bracket. Most likely someone drilled holes to mount a luggage rack, most of that aftermarket stuff back then had to be made to fit.

 

[ballbearian]

Greetings gentlemen, I'm here with another update.

I was able to track down the right cylinder firing issues with a timing light. Very thankful for ballbearian's recommendation of purchasing one.
The right spark plug turned out to be very carbon fouled when I pulled it. Pitch black and dry. I cleaned it with carb cleaner and a towel. The right cylinder is firing now with the spark plug boot seated fully on the plug.
I think it got fouled in the midst of trying to tune the carbs with bad mixture settings. Also, at one point during tuning the carbs, I noticed "exhaust smoke" shooting out of the right cylinder spark plug hole. I was guilty of not tightening the plug down all of the way. Another 1/8th of a turn tightened it correctly. I never want to strip anything on the aluminum engine, so maybe I was a bit overly cautious there.

Next, I got on the phone with Steve and he walked me through the entire points timing setup. This was due to the timing on the right cylinder firing a little late. I ended up installing the Japan manufactured points plate from CMC. I accidentally stripped the screw threading for the right point on the original plate about an hour before I phoned him. I was very upset about that because I was aware of how shallow the threading was. But, in the midst of things, the new points plate gave me new points, felt, and wires. I also lighlty sanded the contacts to get rid of whatever material was on there. When I was done I used the recommended PJ1 Chain Lube for the felt. I wasnt sure how much to apply, I'll provide a picture to verify.

Concern#1: I did have to shift the points plate far to the right(clockwise) to set the left point. Is it normal for it to have to shift that far?



After verifying precise timing marks on both L & LF with the strobe light, I decided to start tuning the carbs.

When adjusting the idle screws there is a lot of "afterfire" from the exhaust pipes when I get the bike to 1200rpm. The pipes towards the rear give off a "gurgling" sound. Revving the engine sounds pretty bad. The bike will idle fine at 800rpm, but of course that isn't at spec.
I currently have the fuel mixture screws at 3/4 turn out. If I adjust them to a 1/2 turn, the pipes get very hot and there is white smoke. Too lean. When I adjust it to 1 full turn out, the engine seems to sputter, maybe too rich. So I've been keeping it at 3/4 turn.

The carbs:

I noticed that when I have the idle screws all of the way backed out, the left carb idle screw is a lot higher from the arm than the right one is. I’ll have to readjust the left throttle plate to let it be more “closed” than the right one. Not sure why I was ok with that the first time around when adjusting the throttle plates.

Concern#2: Before I redo the carbs, (cleaning and adjustments), I want to be sure that my exhaust isn’t causing any air leaks to affect the idle. Also, whenever I’ve picked up the exhaust after removing it, I can hear rattling on the inside. I’ve highlighted below where I can feel air come out with the engine running.

It is exciting to make progress but don't bite off more than one elephant at a time.

Get the points and timing as perfect as possible before messing with the carbs.
For future reference, don't file/sand new points, just clean them with some solvent. Only need to file them after they are used and have a little bump on the contact face.
Ignore the adjusting notch on the plate edge, all that matters is the timing of each point (use the strobe after an initial static setting). And, of course, gap. It would be great to hold up the old plate next to the installed new one for a side by side pic to compare. It may be an easy fix to spot a weld and re tap that stripped hole. It's good to have a backup and until the new plate/ points proves to work right.
Try to ignore the muffler sounds at this point. Air leaks at the intake end of the carbs is a more primary issue. You can spray a bit of WD40 right on the boots/intake to see if rpms change. If so you have intake leaks which must be fixed before any effective carb tuning. Just clean and properly torque the plugs for now. As AD said exhaust leaks down steam are not a concern now. Both pipes are warm/hot, correct?

Sounds like the carb synch and balance is out of whack trying to accommodate a loose plug and flakey plug cap contact. Need to go back to initial bench carb settings for idle stop and mixture,

 

[Danager4792]

It is exciting to make progress but don't bite off more than one elephant at a time.

Get the points and timing as perfect as possible before messing with the carbs.
For future reference, don't file/sand new points, just clean them with some solvent. Only need to file them after they are used and have a little bump on the contact face.
Ignore the adjusting notch on the plate edge, all that matters is the timing of each point (use the strobe after an initial static setting). And, of course, gap. It would be great to hold up the old plate next to the installed new one for a side by side pic to compare. It may be an easy fix to spot a weld and re tap that stripped hole. It's good to have a backup and until the new plate/ points proves to work right.
Try to ignore the muffler sounds at this point. Air leaks at the intake end of the carbs is a more primary issue. You can spray a bit of WD40 right on the boots/intake to see if rpms change. If so you have intake leaks which must be fixed before any effective carb tuning. Just clean and properly torque the plugs for now. As AD said exhaust leaks down steam are not a concern now. Both pipes are warm/hot, correct?

Sounds like the carb synch and balance is out of whack trying to accommodate a loose plug and flakey plug cap contact. Need to go back to initial bench carb settings for idle stop and mixture,

There were definitely a lot of elephants bitten off at once during that post

The timing is currently as perfect as it can be. Firing directly on LF & F marks on the rotor using the timing light.

Thanks for the tip on not sanding the points when they are new. They had some sort of crusty material where the gaps are. It was light sanding until they were clean.

The original plate and this Japanese made reproduction plate are identical in my eyes. I can post a picture of them next to each other. As with all reproduction parts, I'm sure a dial caliper would tell us the true answer with the thickness of the plate, etc.

I cleaned the carbon fouled plug and the cylinder is firing now with the spark plug cap all the way seated. And yes, both pipes are equally hot to the touch. They have always been different temps, glad this is sorted out now.

I asked about the exhaust because I didnt know if those pinholes would cause air leaks, I'm thankful for the clarification on that.

Current problem is a very ugly idle @ 1200rpm. Gurgling noises from the exhaust pipes. Sounds bad when turning the throttle.

I'm going to take the carbs off and get the throttle plates both equally level to one another. When both plates are in the "closed" position(idle screws backed fully out), the left idle screw arm sits quite a bit higher than the right one. That is work I'm guilty of doing the last time I had the carbs off. I'm also going to blow the passages out with an air compressor and clean the jets. I'll also check the idle jet at the back of the carb that was mentioned on this post before.(Cant remember who or I would give credit)

 

[ballbearian]

There were definitely a lot of elephants bitten off at once during that post

The timing is currently as perfect as it can be. Firing directly on LF & F marks on the rotor using the timing light.

Thanks for the tip on not sanding the points when they are new. They had some sort of crusty material where the gaps are. It was light sanding until they were clean.

The original plate and this Japanese made reproduction plate are identical in my eyes. I can post a picture of them next to each other. As with all reproduction parts, I'm sure a dial caliper would tell us the true answer with the thickness of the plate, etc.

I cleaned the carbon fouled plug and the cylinder is firing now with the spark plug cap all the way seated. And yes, both pipes are equally hot to the touch. They have always been different temps, glad this is sorted out now.

I asked about the exhaust because I didnt know if those pinholes would cause air leaks, I'm thankful for the clarification on that.

Current problem is a very ugly idle @ 1200rpm. Gurgling noises from the exhaust pipes. Sounds bad when turning the throttle.

I'm going to take the carbs off and get the throttle plates both equally level to one another. When both plates are in the "closed" position(idle screws backed fully out), the left idle screw arm sits quite a bit higher than the right one. That is work I'm guilty of doing the last time I had the carbs off. I'm also going to blow the passages out with an air compressor and clean the jets. I'll also check the idle jet at the back of the carb that was mentioned on this post before.(Cant remember who or I would give credit)

Not really concerned about plate thickness but the orientation of the points on the plate because that will effect the interaction of the rubbing heels on the center cam lobe, so just a straight on view would be good.
I bet the 'gurgling ' noises are due to internal muffler issues (AD pointed out that screw holes indicate attempted repairs), IOW, not a carb issue. If internal baffles are loose then all kinds of hideous noises may happen.
LDR has advised using soft copper wire as a sort of gauge to set the throttle plate idle position. Great idea. If your throttle arms are different, don't worry about it as the only thing that matters is the actual position of the plates at rest, not the number of turns or threads showing on the screws.
Be thorough with idle jets and their passage ways. Use carb spray and a single wire brush bristle if you have to, and a magnifing glass to inspect each hole..

 

[Danager4792]

I have to remove the exhaust to take the carbs off, which I am doing right now.

There is rattling inside of it. This is a pic of the top pipe that leads to the right cylinder. This ‘object’ is loose and rattling around.

 

[ballbearian]

Well, it's not doing anything being loose. If possible to snag , bend , grab and pull it out then maybe you'll have less 'gurgling'. I'm pretty sure it's not hurting anything but your ears.

 

[ancientdad]

I have to remove the exhaust to take the carbs off, which I am doing right now.

There is rattling inside of it. This is a pic of the top pipe that leads to the right cylinder. This ‘object’ is loose and rattling around.

Very typical of CL exhausts at this stage of life, sad too because when tight and in good condition the CL450 exhaust was one of the best sounding of all Hondas of that era. Try to ignore the mechanical noises while listening for the actual firing notes of each cylinder while tuning the carbs once you get them as right as they can be. Experience in hearing the strength of each cylinder can help you tell if one is firing more strongly than the other, which helps in idle balance. It's a learning process that you've really just begun, and for now there are a lot of distractions in the mix which makes it harder for you. You're getting there, I can tell simply by the improvement in familiarity you've shown with the components you're spending more time with.

 

[Danager4792]

Very typical of CL exhausts at this stage of life, sad too because when tight and in good condition the CL450 exhaust was one of the best sounding of all Hondas of that era. Try to ignore the mechanical noises while listening for the actual firing notes of each cylinder while tuning the carbs once you get them as right as they can be. Experience in hearing the strength of each cylinder can help you tell if one is firing more strongly than the other, which helps in idle balance. It's a learning process that you've really just begun, and for now there are a lot of distractions in the mix which makes it harder for you. You're getting there, I can tell simply by the improvement in familiarity you've shown with the components you're spending more time with.

Thanks for the compliment. It’s been a learning curve trying to learn the correct terminology. I’ve accidentally referred to the rotor as the stator/flywheel/crankshaft etc. Then sometimes I stumble whether I’m talking about the exhaust, mufflers, or headers lol.

Right now I’m going to prioritize and use process of elimination. I have the carbs off now. Gonna clean them spotless and adjust the left throttle plate resting position. Then go from there.

 

[Danager4792]

Merry Christmas Everyone!

I have not made much progress on the 450, as a busy holiday schedule has restricted me from doing so. I will be returning with revenge and great fervor!

I was able to get outside for a few mins yesterday to compare the front brake to the parts diagram.


I noticed that the brake arm stay is bent. And as Tom pointed out, I’m missing a washer. That came in the mail yesterday. Is this ok being bent? I’m not sure if that arm stay would be able to bolt down if it was completely straight. Maybe the washer would make up for the clearance.



Also, I noticed I’m missing a cotter pin. Would it be ok to get one from a hardware store or need to order genuine Honda?

 

[ancientdad]

Merry Christmas to you and yours as well.

Any cotter pin will do, but don't forget to at least put a lock washer (or an original lock tab if you can find one) on the torque arm bolt in the front brake backing plate.

 

[Danager4792]

Merry Christmas to you and yours as well.

Any cotter pin will do, but don't forget to at least put a lock washer (or an original lock tab if you can find one) on the torque arm bolt in the front brake backing plate.

Here is the one I ordered. Is this the original lock tab?

 

[ancientdad]

It is, hope they didn't gouge you too badly for it.

 

[Danager4792]

It is, hope they didn't gouge you too badly for it.

$8.99 to be exact. Found the cheapest listing. For safety purposes, I didn’t mind the price.

 

[ancientdad]

$8.99 to be exact. Found the cheapest listing. For safety purposes, I didn’t mind the price.

Not as horrible as I expected, almost worth it actually. If they still sold them at Honda dealerships today you'd probably pay $3 or $4 at least, so not bad considering.

 

[Danager4792]

Hello everyone, two nights ago I had a HUGE breakthrough on this bike… The biggest improvement yet. Here’s the update:

With the bike still idling very rough, ‘afterfiring’, and refusing to hold 1200rpm, I decided to revisit the carbs for about the fourth or fifth time. I decided to thoroughly inspect and go through them in a very serious manner to figure out what I previously had missed.

First, I set the carb bodies in a steel pot of water. I had the temperature at about 160F with a few drops of dawn dish soap. I let them slow simmer for about 30 mins. I had the brass jet pieces submerged in the top of the water with a strainer.

This was the result after the heated bath. I am assuming this could be rust from the gas tank that didn’t get removed all of the way. If this problem persists, I will revisit the gas tank.



Next, I blew out every carb passage with an air compressor. I inspected every jet with a light. I noticed that one of my slow jets(the piece that screws in underneath the #38 jet), was almost clogged! I made a decision to cut and use a guitar string from my Gibson Les Paul. This was a very painful thing to do, but had to be done. They were old and needed to be changed anyway.

Pictured Left: Original slow jet


After cleaning


Next, I ordered a genuine Honda gasket set for both carbs off of eBay, so that I could try their float bowl gaskets. HUGE improvement. They fit perfectly with no leaks, and don’t impede the float bowl. Completely different from the CMC set I ordered when I first got the bike.

The carb slides passed the straw test.
Floats checked out at 20mm each carb.
I then made slight adjustments to the left carb throttle plate to close better.

I set the fuel mixture screws at 3/4 turns out, and set the idle screws to match each other.

After putting the carbs back on I couldn’t believe what I heard when I started it. The idle was at a solid 1200rpm and both exhaust pipes were hot. I stood there in disbelief.

This was about 5-10 mins after I fired it up.

Tires, suspension, brakes are probably upwards of 45+ years old… but I couldn’t help but finally ride it in the backyard. This was my first time operating a motorcycle clutch. My first two cars were a manual transmission, so I was familiar with general operation.

Still a lot of work to be done. The idle screws and the springs they sit in are loose. They unscrew themselves over time with throttle operation. I was thinking about either painting the screws or tightening the springs. I will have to get the headlight back on too. Even though I was going 5mph in circles I was smiling from ear to ear..

 

[ancientdad]

Completely different from the CMC set I ordered when I first got the bike.

THIS is exactly what we mean by aftermarket kits being poor, and it's even worse when you can't use just the gaskets.

The idle screws and the springs they sit in are loose. They unscrew themselves over time with throttle operation. I was thinking about either painting the screws or tightening the springs.

I suspect the throttle plates or shafts are still part of the issue there, but I'll tell you that you've gotten it as close as most would ever hope to get on a bike and set of carbs that clearly have led a rough life. The idle sounds great compared to anything previous, and the throttle response and drop back to idle is good. Well done brother, you've made great strides for someone with virtually zero experience and knowledge prior to this effort. You should stretch the idle screw springs a little to hopefully better hold the screws still, but for now you should congratulate yourself on the job done so far. Replacing all 4 cam bearing gaskets with no prior experience, then points and timing and now complete, successful carb overhaul - and the results speak for themselves.

 

[Danager4792]

Would also like to add that I swapped out the original #125 main jets(used on the early 14H carbs), for #130 Keihin main jets per Steve’s recommendation.

Thanks for the words of encouragement AD. Can’t believe I have made it this far. There were moments of sheer frustration, but that 10 minute ride made everything worth it! Definitely couldn’t have done it without the crew here. There will be more fine tuning to come, but this is a major victory.