CL350 Doesn't Have Any Power

[drh994]

I'm getting a little stumped on this one guys. I'm hoping someone here can give me a little guidance. I've been doing an full electronic upgrade to the '72 cl350. I put on a Pamco Ignition, Dyna Coils, new rectifier, new stator, new spark plugs, and new spark plug wires. I have all of them installed and still can't seem to get full power out of the bike. I opened up the carbs and they're clean. I'm getting a great spark out of both plugs. I've adjusted the timing some, advancing and retarding, and neither seemed to help. I have 125 psi in the left cylinder and 120 in the right, so that shouldn't be the issue. I'm starting to run out of ideas. What else should I check? The only thing I haven't messed with yet has been the valve clearance. Could that cause the lack of power out of the bike? Or is there something else I'm forgetting to check?

 

[Rich Ard]

You're pretty low on compression - could be partly the valves being out of adjustment. You didn't mention sychronizing your carbs, either.

 

[Sonreir]

Compression specs for you bike says it's time for a rebuild if the compression is under 150 or so. That compression reading is very low. You should do a leakdown test to figure out where the leaks are.

 

[drh994]

Alright, here's an update on the bike. I started messing with the valve timing. The issue I'm noticing is that the rocker arms won't feel loose until the rotor is well past the LT mark. If you look in the pictures, you can see the rocker arms start to feel loose at the arrow mark and not the LT mark. How did something like this happen and how can I adjust it back? I'm thinking that could be why I'm not getting power out of the engine.

 

[SONICJK]

Cam timing?

 

[drh994]

I've never opened the engine on this one but it does seem like the cam is off. The thing is though, I've had the bike running what I thought was right in the past. Then it lost it's power. I thought it was electrical issues but now was I wrong on that assumption? How could the cam timing change?

 

[SONICJK]

If your cam chain tensioner comes loose you can jump a tooth on the cam sproket

 

[drh994]

So are you thinking I need to open the top end up and check that cam then? Is there anything else it could be? It doesn't sound like it really.

 

[SONICJK]

Have you adjusted the valves? The flat head is supposed to face a certain way (check your manual).

 

[drh994]

I'm having a hard time adjusting my valves because I can't get the rotor into the right position and stay there for me to adjust them. The left cylinder won't be in TDC when I have the rotor lined up at the LT mark. That's what I was trying to do when I noticed this problem.

 

[SONICJK]

If the cylinder is not at TDC at the LT mark then your cam timing is off.

Otherwise grab a wrench and a clamp, hold the wrench at the LF mark and clamp it to the frame so it cant move.

Loosen all of your valves all the way loose and start from there, you may just have them way too tight

 

[HerrDeacon]

This is how I clamped mine to stop it from rotating past the mark.

 

[Rich Ard]

Re: Re: CL350 Doesn't Have Any Power

If the cylinder is not at TDC at the LT mark then your cam timing is off

+1. Start here.

 

[SONICJK]

This is how I clamped mine to stop it from rotating past the mark.

I use those exact same clamps for the exact same purpose 8)

 

[drh994]

OK, here's the latest. I started messing with the bike some more. I took off the point plate so I could check the cam timing from the mark behind the plate. When the rotor is at LT, the mark is at 12 o'clock. I also cracked open the cylinder cover so I could take a peak at the actual cam sprocket and chain. I didn't see anything that looked suspicious there. To me, the cam timing looked right. By looking at these things, am I right? I'm trying to avoid taking the engine out altogether just to check the cam timing.

So I started messing with the valves again. I can get the left intake valve to move freely at TDC but I can't seem to get the exhaust valve to move freely at TDC. I've been trying to adjust the valve clearance but I haven't had any luck getting it to free up. Am I missing a trick with this one?

Thanks for all the help guys. I really appreciate it.

 

[SONICJK]

Just loosen the valves up whenever you can in the rotation. If its too tight to loosen at TDC, loosen it when its not too tight.

But what you need to do is put the rotor at TDC, and then look at your cam sprocket, theres a flat spot on the rubber on the sprocket that should exactly line up with the flat top of the gasket surface on the head. If its off, even a little thats your problem.

Funny i googled that image, said damn that hand looks familiar, and yup its my image.

 

[drh994]

I checked the cam sprocket like you said. I found the flat part on the cam sprocket. It is on the top and level with the cylinder head. One thing I messed with when I turned on the bike was manually use the throttle on each carb instead of the throttle. When I do that, the right cylinder works just fine but the left cylinder doesn't hardly work at all. Sometimes if I adjust the ignition timing it gets slightly better but it never works right. That tells me that the valve timing is off on the left cylinder. I've been messing with that and can't seem to get both rocker arms to be free at the same time. Now they are seriously close to being able to but they still haven't yet. Should I keep on that path to getting it fixed?

 

[SONICJK]

Sounds like you're on the right track,
At tdc both rockers should be loose, if you cannot make them loose something is bent most likely.


With the valve cover off turn the engine slowly using the 14mm bolt on the alternator rotor. At the same time use your other hand to fiddle with one of the valves on the left cyl. When it's loose stop turning and loosen it up as much as you can. (Back off the lock nut and use a flat head to get it loose)
Then repeat with the other valve.
Then turn to LT and see where you stand.

If you can't do this i would say you're going to need to look into tearing the rockers out and seeing what's up.

 

[Sonreir]

Sounds like you're on the right track,
At tdc both rockers should be loose, if you cannot make them loose something is bent most likely.

Only on every other rotation of the crank. Half of the time the rockers would be loose, but the other time they would not because the piston approaching TDC would be the end of the exhaust stroke/beginning of the intake stroke.

Best angle to check is about 90° ATDC of the power stroke.

 

[SONICJK]

Only on every other rotation of the crank. Half of the time the rockers would be loose, but the other time they would not because the piston approaching TDC would be the end of the exhaust stroke/beginning of the intake stroke.

Best angle to check is about 90° ATDC of the power stroke.

Good call,
Completely forgot to mention this!