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    AD

CB450K0 - Teebo build

You put it in but didn't tighten it up until you get all the bolts started, then forgot to tighten this one. Or at least that's what I do.
 
You put it in but didn't tighten it up until you get all the bolts started, then forgot to tighten this one. Or at least that's what I do.

That is my theory. These were headers from a K1+. So it took some creativity. On and off over and over.

I’m fairly certain I just didn’t tighten it down.


‘69 CB350
‘68 CB450K0
 
First oil change.

I’d call oil condition distressed. Like it hadn’t been changed in years.

I’m straining it now.

Oil filter wasn’t bad. There were small number of little flakes. Then the normal sludge with a very slight metallic glint. But too small to pick out though.

Another operator error I’m sure. But the oil filter nut was slightly loose. Thankfully I did properly use the lock washer. Corrected that.

Timing was off. Slightly retarded on both sides. Same amount actually. Almost as if the base plate rotated. But it was tight. Also corrected.

Valves were still where I left them.


‘69 CB350
‘68 CB450K0
 
That's mostly good news with a little remedial effort to fix the little things discovered. Don't be hard on yourself, remember the oil flow issues I had with my red 450 due to my own mistake despite all my experience with this engine. Stuff happens, and fortunately none of it was damaging.
 
That's mostly good news with a little remedial effort to fix the little things discovered. Don't be hard on yourself, remember the oil flow issues I had with my red 450 due to my own mistake despite all my experience with this engine. Stuff happens, and fortunately none of it was damaging.

Ditto what AD says. I'd happily trade places with you right now.
 
Ditto what AD says. I'd happily trade places with you right now.

No way!

I worried about a bad outcome the entire time I was rebuilding. I wasn’t worried at all about anything other than engine. I’ve never done it before.

I was literally scared when starting it. I still don’t feel out of the woods. What if I made some mistake, months ago, and it just hasn’t manifested yet?

I eventually just accepted that while I’d probably take a short break to lick my wounds, I’d be right back at it.

Learning from my mistakes and all that. ;-)

I think you and I covered a lot of ground. We should feel some sense of accomplishment no matter what. You’ll get it worked out and have years of enjoyment and pride from it.


‘69 CB350
‘68 CB450K0
 
You're quite right my friend. I felt like I was pushing the limits of my skill set doing the work that did, but I pushed my limits and gained a little bit of confidence (not too much, just a little) along the way. I will feel some sense of accomplishment if I get across the finish line and you certainly should feel that right now...you're riding a very cool classic bike that you restored yourself. Kudos.

I have at least 2 other engines in my garage that need attention and I will tackle them myself, one at a time, asking lots of stupid questions along the way.
 
I have at least 2 other engines in my garage that need attention and I will tackle them myself, one at a time, asking lots of stupid questions along the way.

And we will be here to help you, God willing and the creek don't rise. And remember what Jim always says, the only stupid questions are the ones you don't ask. (y)
 
Troy and Teebo, you guys are doing great even with the hiccups along the way. Yeah, you've made mistakes and learned what not to do along the way. Some people never learn and give up.
 
We all make mistakes, and we all have plenty of experience kicking our own butts. Over time you just get used to it. You've done some fine work. Try to relax and enjoy the ride from time to time. See if you can burn a full tank of gas before you dive in again.
 
We all make mistakes, and we all have plenty of experience kicking our own butts. Over time you just get used to it. You've done some fine work. Try to relax and enjoy the ride from time to time. See if you can burn a full tank of gas before you dive in again.

Well so far they’ve just been minor. Not sweating it.

No plans to start a new one. Going to ride out the season with what I got. Fixing just what needs to be done.

My turn back to my 350 and do the engine and frame on that in the fall.


‘69 CB350
‘68 CB450K0
 
Maybe I should start other threads since I’m into more specific issues now.

But is it worth it to pick up some later 14H carbs? Mine has the earlier 14C. My limited understanding is the later version has some improvements.

They are out there and not that expensive.


‘69 CB350
‘68 CB450K0
 
Maybe I should start other threads since I’m into more specific issues now.

But is it worth it to pick up some later 14H carbs? Mine has the earlier 14C. My limited understanding is the later version has some improvements.

They are out there and not that expensive.


‘69 CB350
‘68 CB450K0

While some here choose to start peripheral threads for some of their little challenges along the way, I feel like a project thread should be all-inclusive with every little issue that you come across related to the project all in one place so others later don't have to look around for the solution to one thing that cropped up during the rest of the project. I mean, the project isn't finished until all aspects of it are resolved and completed, right?
 
I have an issue where it’s hard to start when it has been sitting awhile. Like at least a day.

I mean it takes 3-4 attempts with the starter. Not short bursts either.

Once the bike has run, even for just a bit, it fires right up. For example, I drove it 12 miles and stopped someplace for dinner. Came out an hour later and boom started up with just a blip of the starter.

I have:

- Checked for leaks around the boots. Again.
- Went back through a carb clean, using compressed air to blow out passages. Checked float height. I believe the jets are stock and the right size. The only thing that may be non-stock are the float valve bits.
- I noticed yesterday that when I hooked up my strobe, it’s RPM for the right was at least 300 less than left. Didn’t matter what I did with adjustments. I still had older points that looked pitted (or just old) to me so I replaced them. This seems to have corrected that.
- Checked coil resistance. They matched a new spare set I have. The coils are new, along with the condenser.
- I didn’t test the condenser by charging it and checking for a spark when grounded. But I also don’t see what I’d call too many sparks from the points. A little one here and there.
- It doesn’t matter if air filters are on or off. Seems to run the same either way.
- It doesn’t matter if the points cover is on or off. I don’t believe there is a short there. At least from the cover.
- Compression at 150 miles is ~160. Both are within 2-3 psi of each other.
- I have B7ES plugs with resistored caps. New plugs.
- Near as I can tell the carbs are synced. Wish I had known a port in the intake would be handy for hooking up a vacuum gauge.
- I do believe I have good grounds. Or at least I get the continuity beep. But now I realize I should look at the actual resistance.

BTW. When riding it feels great. I think it runs better than my 350 that I’ve spent more time on.

One other thing. It’s typical that the first time I hit the starter, I hear a cough. A brief ignition. Then nothing. Eventually it catches and from there everything is normal. A little choppy at first then after a short time it smooths out. This makes me wonder if it’s just way rich. But various choke positions don’t seem to matter much.


‘69 CB350
‘68 CB450K0
 
I have an issue where it’s hard to start when it has been sitting awhile. Like at least a day.

What's your start-up procedure? I know you said that choke positions don't seem to matter, but do you typically use the choke? And do you blip the throttle at all while engaging the starter?
 
What's your start-up procedure? I know you said that choke positions don't seem to matter, but do you typically use the choke? And do you blip the throttle at all while engaging the starter?

I don’t touch the throttle. I think. I’ll make special note next cold start.

Typically I would use more choke when it’s colder. It’s in the 80’s F here. So I’ve been trying in the 30-50% range on first attempt.

I’ve tried other variations. I say it doesn’t have effect. But it does. Like with choke 100% on, it will likely never start. But all the way off doesn’t either when cold.

The overall procedure is turn the fuel valve on. A minute later I’ll turn the key, position the choke, hit the starter.


‘69 CB350
‘68 CB450K0
 
I may speak blasphemy here, but I think the slightest blip of the throttle when you hit the starter might make a difference. I would also choke it, but would not let it run long with the choke after it fires (in warm weather).

Edit: My reasoning here is that the throttle plate usually partially covers the pilot bypass orifice in the stock carbs and a slight opening of the throttle will expose that pathway for fuel to richen the mixture. I sometimes lift one throttle arm very slightly when kicking over my bike and my experience is that it helps with cold starts.
 
I may speak blasphemy here, but I think the slightest blip of the throttle when you hit the starter might make a difference. I would also choke it, but would not let it run long with the choke after it fires (in warm weather)

I thrive on blasphemous techniques. I’ll try it.


‘69 CB350
‘68 CB450K0
 
I thrive on blasphemous techniques. I’ll try it.


‘69 CB350
‘68 CB450K0

Even when the ambient temp is 80°, you still need full choke if only for a few seconds. The engine internals are "cold" despite outside temp, meaning zero combustion warmth and the carb bodies are as well. And if you turn the throttle even a little bit you actually make it harder to start. Remember these carbs do not have accelerator pumps, so no amount of turning the throttle when cold does anything but reduce the potential vacuum draw that helps bring a dose of raw fuel into the combustion chambers to get things going. Keep your hand on the choke and off the throttle, push the button and be ready to reduce the choke quickly once it's running for a few seconds.
 
Even when the ambient temp is 80°, you still need full choke if only for a few seconds. The engine internals are "cold" despite outside temp, meaning zero combustion warmth and the carb bodies are as well. And if you turn the throttle even a little bit you actually make it harder to start. Remember these carbs do not have accelerator pumps, so no amount of turning the throttle when cold does anything but reduce the potential vacuum draw that helps bring a dose of raw fuel into the combustion chambers to get things going. Keep your hand on the choke and off the throttle, push the button and be ready to reduce the choke quickly once it's running for a few seconds.

This is what I’ve tried. I considered my starting technique. I just seem to have worse luck if I go full choke.

I thought it was normal to not use throttle.

I’ll try more.


‘69 CB350
‘68 CB450K0
 
If you mean throttle, you're welcome to experiment and if it works for your bike and carbs then good, but by and large the least throttle application is best.

I meant I’d try the recommended technique more.

Heck. For all I know I’m unconsciously twisting the throttle slightly.


‘69 CB350
‘68 CB450K0
 
I blame the old float bowl system, vented to the air. After 4 - 5 days the gas level has gone down because of evaporation and, unless you are a patient person, you may be starting it before the gas has refilled the bowls. Try turning on the petcock as the first thing you do, before you put on the jacket and helmet, before you wheel it out of the garage, before you run into the house to get the cell phone you left on the counter in the kitchen.
 
I blame the old float bowl system, vented to the air. After 4 - 5 days the gas level has gone down because of evaporation and, unless you are a patient person, you may be starting it before the gas has refilled the bowls. Try turning on the petcock as the first thing you do, before you put on the jacket and helmet, before you wheel it out of the garage, before you run into the house to get the cell phone you left on the counter in the kitchen.
Float bowls have to be vented, otherwise under certain conditions they would go to negative pressure.
 
Good news, bad news.

Good news is AD might be on to something. He should write a book.

Bad news is it idles better but sputters like mad at 6K. This is new behavior. Would be willing to bet my own money I did something wrong. Though I can’t imagine what. I’ve cleaned/rebuilt carbs so much it doesn’t even stress me at all.

Don’t tell me. I want to figure it out.


‘69 CB350
‘68 CB450K0
 
Good news, bad news.

Good news is AD might be on to something. He should write a book.

Bad news is it idles better but sputters like mad at 6K. This is new behavior. Would be willing to bet my own money I did something wrong. Though I can’t imagine what. I’ve cleaned/rebuilt carbs so much it doesn’t even stress me at all.

Don’t tell me. I want to figure it out.


‘69 CB350
‘68 CB450K0

Got both chokes connected together so the right one doesn't slip closed on its own? Obviously I don't know what's wrong but it's an easy one, just like when the detent "spring" for the choke lever doesn't put enough pressure on the little notches in the lever and it turns a little on its own.
 
Got both chokes connected together so the right one doesn't slip closed on its own? Obviously I don't know what's wrong but it's an easy one, just like when the detent "spring" for the choke lever doesn't put enough pressure on the little notches in the lever and it turns a little on its own.

That was one of my first thoughts actually. Since that is also right in the path of putting them back on.

But nope. All seems square.

This is the amazing part of having two bikes. I rode my 350 the other day and had a blast.


‘69 CB350
‘68 CB450K0
 
Who knows? It's just punchier to have a number than to say "Well, you know, a bunch of carb problems turn out to be electric."
 
Still not solved.

I went through every ground. I don’t know how I could be more certain. Battery fine.

Even though everything checked out with the meter, I swapped in some spare coils and condenser. No change. I wasn’t expecting it to. Nice to know though.

I think I have a couple issues.

I was getting an occasional backfire through the carb on the right. Turns out I had a leak again. I don’t like these boots. This isn’t the first time. I even had a thin smear of Honda bond silicone on it. At any rate, redid it. Back fire didn’t happen last ride. I also found what’s looks like higher quality boots from the UK. No idea really. But they say they are and people don’t lie on the internet. Right?

This last ride was a little better. The sputter is really in the upper 5k. On the other side of 6k it’s fine. I had this exact problem on my 350 once.

I did recheck my float levels. When I first rebuilt the carbs I felt the float plunger was worn so I just used the kit seat and plunger. There is a difference in the seat I discovered (last night). The hole is smaller and the plunger goes in deeper. I used stock seats and new plungers. 100% sure I don’t have a float level problem.

Left spark plug is sooty black. Right is fine. So that’s where I’m going next.

Now if it would stop randomly threatening to storm. Every. Day.

I wonder if I’ll ever get this right with pod filters. I would take a rougher idle and smoother acceleration any day. If I could figure out what I did to get it there.


‘69 CB350
‘68 CB450K0
 
These Daiichi points I put in are interesting.

To get it timed left point gap had to be set at the lower range, right at the upper.

On rechecking it, I think maybe it’s worse than that really.

Anything to be done about that?

As a test I put the old points back it. They seemed to clean up ok. Left ends up being .33mm and right ~.36mm.


‘69 CB350
‘68 CB450K0
 
These Daiichi points I put in are interesting.

To get it timed left point gap had to be set at the lower range, right at the upper.

On rechecking it, I think maybe it’s worse than that really.

Anything to be done about that?

As a test I put the old points back it. They seemed to clean up ok. Left ends up being .33mm and right ~.36mm.


‘69 CB350
‘68 CB450K0

As I recall, Daiichi is the lowest quality brand that Honda used.
 
Well I officially have no earthly clue.

Still sputters. While better choke technique helped, it’s still a PITA to start. Like I’ve come to hate starting it cold.

Since I discovered this I’ve:

- Went back through carb clean a float level check.
- No vacuum leaks at the moment
- Grounds seem ok
- points (but back to originals)
- coils and condenser
- spark plugs (because why not)
- check idle and throttle sync. Again.

None of these things made a bit of difference and I’ve run out of parts to blindly swap out. ;-)


‘69 CB350
‘68 CB450K0
 
The only thought I have is one that I finally came up with on my K0. I had a very hard time getting it running from cold. What helped was to put a charger on the battery, one that puts out up to 10 amps, and then try to start it, right away, no waiting needed. Every time - zoom - it starts fast. Once it's been running, even if only for a couple of minutes, it will restart easily with its own battery and starter. When it's cold I have to use the charger. Maybe it needs a bigger battery or a new battery, maybe it needs a kick in the ass, maybe I don't know why, but it works. I hope it works for you.
 
That would add to the knowledge that these ignition systems have to be top condition for proper performance in every aspect due to the battery size. I'm guessing the factory dwell isn't long enough for a hot spark at cranking rpms while the starter is drawing some of the battery amperage. I'd bet if you modified the breaker cam lobe on the advancer like I did it would start more quickly with the electric start.
 
Interestingly enough I decided to really really clean the pilot and slow jets and passages. And followed the doc in the VHT library, Bill Lanes carb setup.

The default setting makes the idle fairly high as a start point.

Started right up. Just a few ago, after sitting all night, two blips got it going.

Idle is around 1500-1600 when hot though. Maybe higher really.

The sputtering makes it unridable really. Sometimes it’s severe. Sometime just when I shift at 6k into second.

Since I don’t know what’s going on I’ll let it sit until something comes to me.

CB350 weekend it is. I’ll try making it jealous.


‘69 CB350
‘68 CB450K0
 
Earlier in your thread you mentioned trying a set of later 14H carbs because they could be found cheap? At the time I wasn’t able to respond to that thought but it seems like cheap insurance to have a spare set of carbs and with the known issues of the original 14C Bomber carbs. Only the most discerning eye will ever realize the carbs are a later variety and if it makes the bike run right… well that’s what you are after correct? Given your frustration, if I were in your shoes, I’d consider this option. Just my 2 cents.
 
Earlier in your thread you mentioned trying a set of later 14H carbs because they could be found cheap? At the time I wasn’t able to respond to that thought but it seems like cheap insurance to have a spare set of carbs and with the known issues of the original 14C Bomber carbs. Only the most discerning eye will ever realize the carbs are a later variety and if it makes the bike run right… well that’s what you are after correct? Given your frustration, if I were in your shoes, I’d consider this option. Just my 2 cents.

Absolutely agree. You're not going concours level so make it run right, and slap anyone who tries to get close enough to the carbs to tell which version they are. *nothing to see down there* :)
 
Thing is, it was running right. So what changed? Dunno.

Also, I really need to find stock air filters. No luck so far. I can’t totally blame the carbs just yet.

I’m totally open to later model carbs. It’s never been my intention to create a show bike.


‘69 CB350
‘68 CB450K0
 
The biggest change I made is the slides didn’t always operate smoothly when shooting compressed air into the ports. They tended to get stuck halfway up.

I cleaned them up and they seemed to work correctly.

Just now I redid them. They are practically polished at this point. Super smooth.

No idea if this is related to the sputtering.


‘69 CB350
‘68 CB450K0
 
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