[sbaugz]

LOOKING FOR ADVICE on a friends bike
i've about had it with this CL350. Wondering if anyone has any thoughts.


CL350 that initially ran well. Did a light customization on it including UNI pods and stock headers with EMGO slip ons. Had the carbs rebuilt and re-jetted (supposedly professionally). Got the bike back together and it ran like crap. Cuts out and loses power around 6000RPM. took a look at carbs again- seems OK. Just for the hell of it, we upgraded to a complete dynotek ignition (pickup, wires, coil) . Compression is good. New plugs, new petcock and lines.

Bike still runs like crap above 6000RPM. Below that, its fine- you get to about 6000-6500 RPM and it starts bogging and losing power. In particular, it gets really bad in top gear (5th) when you try to go past 6000 RPMs. Only tops out at about 60MPH before it loses power.


Took a look at the carbs myself today for the third time. Everything looks good, except one of the floats was bent and way off, so I figured I would get lucky today, but that didn't seem to solve the issue.

So....... I figured i would do some more troubleshooting. I ran the bike on one cylinder purposely by disconnecting a plug wire one at a time. When I run the left cylinder only, it runs great. I can shift thru all the gears to redline. When I try the right cylinder, it bogs out and loses power around 6000 RPM, similar to my issues that I am having. So it seems something is awry on the right side.

I swapped out left and right fuel lines--- No change. Still loses power on the right side.
I swapped out all the ignition wires, coils, plugs etc from right to left---- No change, which implies its not the ignition. Still loses power on the right side.
I swapped out all the internal carb parts including needles, floats, diaphragms, etc from right to left- No change. Still loses power on the right side.

Any thoughts? Seems like it is probably NOT the carbs or the ignition. Could it be a valve issue? You would think it would run like crap all the time and not just at 6000 RPM and above? I suppose some of you will chalk it up to PODS and tell me that CL350's cannot run properly on PODS. I get that, but if it were jetting or PODS, I don't think it would be acting the way it is.

 

[doode]

What's the primary and secondary main jets?

 

[sbaugz]

What's the primary and secondary main jets?

i honestly don’t know. I’d have to look. The guy who rebuilt them the first time said he jetted them for PODS. If it were a jetting issue, why would it only have the problem on the right cylinder and not the left? Even after swapping all the jets right to left.

 

[doode]

Jetting for pods (not really a real thing) is worthless if you change out the exhaust

 

[Boomer343]

Check the slide and diaphragm on both carbs. Look for pinholes in the diaphragm by shining a light at it.

I clean and polish slides and bores and check for smooth action.

I would also suggest pushing the brass emulsion tubes out and checking that all the holes are clear.

 

[80cb400t]

It would make sense to do a valve adjustment to rule that out. If no change maybe a compression check to make sure you've got similar compression on both sides would be a good idea?
Also, does the dynotek ignition use the points? Is it possible that the points on that side have always been off and the electronic ignition was set that way as well? Seems worth investigating.

 

[sbaugz]

Jetting for pods (not really a real thing) is worthless if you change out the exhaust

It was re-jetted for the exhaust and PODS (supposedly) by the guy who rebuilt the carbs the first time

 

[sbaugz]

Check the slide and diaphragm on both carbs. Look for pinholes in the diaphragm by shining a light at it.

I clean and polish slides and bores and check for smooth action.

I would also suggest pushing the brass emulsion tubes out and checking that all the holes are clear.

Emulsion tubes were removed and cleaned three times. Slide diaphragms were checked multiple times as well. Plus- when I cleaned them for the third time, i swapped slides, diaphragms and emulsion tubes right to left carb and it still only loses power on right cylinder

 

[sbaugz]

It would make sense to do a valve adjustment to rule that out. If no change maybe a compression check to make sure you've got similar compression on both sides would be a good idea?
Also, does the dynotek ignition use the points? Is it possible that the points on that side have always been off and the electronic ignition was set that way as well? Seems worth investigating.

The new ignition does not use points. The problem of losing power actually happened with the original ignition and points. With the electronic ignition installed, it is acting exactly the same. I assume that implies the ignition change was irrelevant

 

[83XLX]

"CL350 that initially ran well. Did a light customization on it including UNI pods and stock headers with EMGO slip ons. Had the carbs rebuilt and re-jetted (supposedly professionally)."

If it ain't broke, don't break it.

I'd say it is a carb problem. That said, have you run it enough to get any color on the spark plugs? If so, what does the right plug look like? I'd check the jets in both carbs to make sure they match. Make sure the two press-in jets in each carb have good o-rings on them and they fit tight in the carb. Also make sure the rubber plug is in the hole beside the two main jets and that it fits tight. If you replaced the carb diaphragms, make sure the slides are indexed correctly to the carb body. Recheck the float heights, make sure they move freely, and verify that you get good fuel flow through the float valves. I'd also make sure the chokes are hooked together between the carbs and are staying open, and try running it without the pods just to take them out of the equation.

 

[doode]

A person can say rejet for pods, but what is that really? Leaner, fatter, shimmed or files the needle, went bananas like crazy pj?

Also, after reading ^^^, make sure the choke strap between the two carbs is hooked up and oriented correctly. Maybe it's slipped and the rt carb is getting choked

 

[Dreadnaught]

After you finish beating up the carbs-do a compression check and a leak down check that will tell you if you have a cylinder or valve problem.
Remember that engine is 40+ years old might be time to freshen it up.
I don't run the stock carbs as they have to many quirks-I use the metal piston ones from the 450-reset float level and install a 35 slow speed jet and Bobs your uncle.
Good luck.

 

[sbaugz]

try running it without the pods just to take them out of the equation.

Running without PODS did not change anything at all.

 

[sbaugz]

After you finish beating up the carbs-do a compression check and a leak down check that will tell you if you have a cylinder or valve problem.
Remember that engine is 40+ years old might be time to freshen it up.
I don't run the stock carbs as they have to many quirks-I use the metal piston ones from the 450-reset float level and install a 35 slow speed jet and Bobs your uncle.
Good luck.

I did a compression test today on a cold engine using the kick starter about 6-7 times. Interestingly, the compressions numbers are pretty high. (i tested compression last summer and both cylinders were 170). Now I am getting 200 PSI today on both cylinders? Does this have any significance?

 

[sbaugz]

A person can say rejet for pods, but what is that really? Leaner, fatter, shimmed or files the needle, went bananas like crazy pj?

Also, after reading ^^^, make sure the choke strap between the two carbs is hooked up and oriented correctly. Maybe it's slipped and the rt carb is getting choked

when I mentioned earlier that the carbs were professionally rebuilt and re-jetted for PODs, I was actually referring to crazyPJ. I sent them to PJ two years ago and he was the one who originally set them up for me with my setup (PODS and open exhaust).

 

[doode]

Hmmm... 83xlx asked about plug color? Anything notable there?
I've had similar issue before but it was solved with coil and condenser replacement. From the sounds of it you did a swap, so maybe your ignition unit? Can you switch to points to test?
Can you test your compression gauge on another bike to see if it also reads high?

 

[LashLarue]

Check the advance mechanism behind the points plate. If it's a conversion to electronic I have not idea how they change timing w RPMs.

 

[twinnut67]

Sure sounds like a fuel issue. Wonder if that carb is running out of fuel due to low float.? Be nice if U could ride it and pull the plugs after that bog. I take it you have new coils ?

 

[Mike1000]

I think you should check the fuel supply back to the tank pick up, maybe it’s only getting enough gas for the closest cylinder also check valve and ignition timing.

 

[jdvorchak]

Sounds like you've beat the carbs to death. I would start by making sure the ignition timing is spot on both cylinders. If reading the plugs doesn't show anything significant quit beating up the carbs. Timing chain adjustment and revisit the valve lash. Are the carbs synced all the way from idle to WOT?