1971 CL350 "Headache" - Dies when warm

[ejether]

Hey all,
I'm stumped on this CL350 I've been working on.
13K Purchased by a friend who like it and thought it was "cute"
Compression is good and it has UNI pod filters on it.

I test rode it, noticed it bogging a little and not revving quite like I hoped. I assumed it was carbs so when I got it home I pulled and cleaned the carbs. I did not replace any brass. Yet.

After carb clean the bowls leaked and the right carb was dripping out the overflow.
But it was running reasonable well when cold on choke and the tank off (started idled etc). When warm it would bog, and the idle would drop till dead. Thinking coil fade, I replaced the condenser and coils with Emgo coils with new wires, new plugs and caps.

Needle seats and needles were replaced using a rebuild kit. I did not replace the jets with then ones from the kits as they were different sizes. Floats were set at 26.5mm

I took it for a spin and it died out. It only has problems when the tank is on, as in, it runs fine from my Auxiliary tank. I have noticed the petcock seems to vapor lock or something so I addressed that and, while warm, I could only get it to run on 1/4 throttle. It would die without throttle. I have disassembled and cleaned the petcock a couple of times, there has never been any rust in it or anything.

I will be installing a Pamco ignition tomorrow but I'm not convinced that will fix anything.

I'm at a loss and getting tired of this thing. Can anyone point me at something I missed? Or something?

This is the first early 70s CB/CL I've worked on so I'm sure I'm not fully with it....
Thanks in advance!

 

[hillsy]

Check that the tank is venting properly - it may be starving the bike for fuel.


Also - does the bike have stock exhaust / air filters / air box? If not, it could be running lean and dying when it gets hot.

 

[ejether]

After quitting on me last night, I was trying to get it going with the tank open and it was still bogging.

It is running with Uni pods and stock exhaust.. It dies faster with the choke on so I don't think it's lean. Unless I'm missing something. PO said they had jetted for pods. I'll pull the plugs and look first thing when I start on it this evening.

Anyone know what the stock jetting should be, or have suggestions on jetting for pods?

 

[ejether]

Playing hooky today.

Pulled the plugs and they are wet. It's not lean.
So carbs, not ignition. Why would it get so rich when riding but not idling?

 

[ejether]

Installed Pamco ignition, found out the timing advance was frozen. I don't know enough to know if that could be the problem when it gets warm?

 

[ejether]

I ended up solving the problem by setting the timing by ear instead of using the timing light. A slightly advanced timing, according to e left cylinder, seems to allow both cylinders to fire. It's still missing a little bit on one cylinder, but I know the advancer has some play in it. One I install a new one, I hope that takes care of itself.