71 cl350 valve clearance too much - help!

B

bbowman

New Member
So i got a 71 cl350 project..wasn't running..rebuilt top end, and has been running ok. Was going to set valves again today and hit a snag...

left cylinder went fine..then started on right..rotated crank until T lined up with mark on stator. exhaust clearance went smooth..then i checked intake. it was REALLY loose. I mean like had probably 1 mm of play. When i tried tightening it the tightest it would get still had about .5 mm of clearance. (just an estimate..might be more or less..but definitely WAY more than .05mm - at least 3x that much).. Am I doing something wrong or is my rocker arm or rocker arm pin really worn down that much that it would be that far off???

I dont understand why it would be only 1 arm/pin out of the 4 when they all have the same # of miles on them (the bike had 16,000 on it). has anyone had similar problems? Am I missing something? Anyone have an idea if it is the pin or the actual arm or something else completely?

Thanks for any help.
 
I think it was probably getting oil because it was actually leaking a little from the seal where the tac drive cover meets the valve cage. I'm wondering if perhaps the valve is stuck open? Next time I go to the shop I'm gonna check for compresion. It doesnt make sense that something could have worn that considerably that quickly..
 
You could have been mis-adjusting the first time? No one is perfect.. But deff do a compression test just to be sure.
 
Not that it would make that big of a difference, but make sure the top of the flat head slot in the adjuster screw is pointed up and away from the engine.

I'm guessing stuck valve. Dump some seafoam in there and then cycle the engine a few times and try again
 
AlphaDogChoppers said:
Was it you I suggested that to and it magically fixed your problem?
Click to expand...

Yezzir it was.
I still owe you a beer or three for that one.
 
I love it when I get lucky on an Internet diagnosis. It makes me look smart in spite of the reality! <G>
 
well figured it out..this shit if going to blow your guys mind..

going off of my idea that valve is stuck open i checked compression in right cylinder and it didnt have shit..at that point i figured i was gonna have to take engine out so i just said f it and did it. a few hours later engine is sitting on my bench... started taking apart and figured i should just take a peek in intake and see if i see anything. a big ol piece of metal was sitting in there...ran over to look at my carb and see this.


pic hosting

notice anything wrong with this picture? YEAH. shit broke off and my engine ate it. found a few pieces stuck in my valve holding it open. a few pieces in intake as mentioned, and a few pieces chilling in my cylinder...

heres the valve that was giving me issues....


pic hosting

The good news: cylinder looks as fresh as the day i honed it. AND got pieces out of valve and seal seems good still and valve doesnt seem bent or anything. filled up the displacement area in the top of the head with some paint thinner and wasnt leaking or anything so i figure its still okay!

So i think i dodged a pretty big bullet here...pretty sure that coulda destroyed my engine if it wanted to..

Soooo does anyone have a spare choke plate they would sell me? ;D
 
You never know!

Haha glad you took the initiative and pulled the motor man that could have been a major disaster
 
Make sure you check the valve sealing surfaces for damage. You may only need a light lapping to clean up...
 
yeah I am so happy that i didn't ruin everything. I just rebuilt the top end a month ago and got the bike running for the first time within the last few weeks and this shit happens to me! my first build too! just my luck... good thing i was only puttering around in my neighborhood.

i filled the displacement area in the head with mineral spirits and it was water tight..does that mean i can safely skip lapping the valves? seems like if its water tight it should be good to go right?
 
Try from the other side as well, dump some solvent in the intake side and see If it leaks into the combustion chamber.

A lapping wouldn't be a bad idea, the only real way to tell if its still good is a leak down test but you have to rebuild the motor before you do that.

Also you're going to have to replace the head gasket I you didn't already think of that.
 
bbowman said:
i filled the displacement area in the head with mineral spirits and it was water tight..does that mean i can safely skip lapping the valves? seems like if its water tight it should be good to go right?
Click to expand...

The usual method is to spray carb cleaner into the port. If no seepage appears on the combustion side, you are good to go. Carb cleaner is lower viscosity than mineral spirits, so would show leakage that mineral spirits might not, but my gut feeling is that you are OK. The valves and seats are a LOT harder materials than those chunks of metal that got stuck in there. So long as the piston didn't hit the valve and bend it, your seal should still be perfect. I would avoid re-lapping the valve unnecessarily. You don't want to make the valve/seat contact area any wider than necessary.

The old adage holds true-If it ain't broke, don't fuckin' fix it.
 
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