I'm still working on my valves.  I had it running, checked the valves, found no clearance on the exhaust valves with 275 shims, had it running, finally got new shims.

#1 question: I had the shims out.  Somehow the buckets got turned on the exhaust valves, and I can't get them out anymore.  How do I turn the buckets if I can't find the notch?  Is there a trick to this?  I'm hoping to avoid having to pull the cam off.

#2 question: I got 270 shims in.  Still no clearance.  Had the bucket trouble above.  Got 265 shims on one side.   Still no clearance.  None.  0 WTF?  I had it running.  How could it be running with the shims so far off?  Am I doing something wrong? 

Thoughts?

Are you sure you're measuring the clearance correctly? If the cam's out of place when you measure, you could get a bad reading. Also, how well was the bike riding before you pulled the shims? If it was running very well, you might be measuring wrong, but if it wasn't running well, it could have had really tight exhaust valves and still sort of run...

Quote from: fred on February 19, 2009, 10:58:17 PM
Are you sure you're measuring the clearance correctly? If the cam's out of place when you measure, you could get a bad reading. Also, how well was the bike riding before you pulled the shims? If it was running very well, you might be measuring wrong, but if it wasn't running well, it could have had really tight exhaust valves and still sort of run...

It was running horribly.  I followed the haynes book to set the cams.  Even then, as long as the round side of the cam lobe is down, shouldn't the clearance be the same?  I've never quite understood that...

 
From my experience, the valve clearances can be quite tight and the motor will still run - in my case, not too badly.  Idle was a little rough, but she still ran OK.  On my last clearance check, I had to go from 2.80 to 2.70 left side exhaust and from 2.75 to 2.65 on the right side exhaust before I could get an acceptable measurement. My clearance gaps are now 0.04 and 0.08 mm, respectively.  I've read somewhere on this site that if the motor is run for extended periods with tight clearances that the exhaust valve seats can recede at a quicker pace.  I have no reason to doubt it.

You may wish to get a much thinner shim than you think you might need (a test shim) to pop into place just so you can see what the actual clearance is to help you figure out the correct size you need to get into the 0.3 to 0.8 mm range.



Mike

Quote from: applecrew on February 20, 2009, 05:52:21 AM

From my experience, the valve clearances can be quite tight and the motor will still run - in my case, not too badly.  Idle was a little rough, but she still ran OK.  On my last clearance check, I had to go from 2.80 to 2.70 left side exhaust and from 2.75 to 2.65 on the right side exhaust before I could get an acceptable measurement. My clearance gaps are now 0.04 and 0.08 mm, respectively.  I've read somewhere on this site that if the motor is run for extended periods with tight clearances that the exhaust valve seats can recede at a quicker pace.  I have no reason to doubt it.

You may wish to get a much thinner shim than you think you might need (a test shim) to pop into place just so you can see what the actual clearance is to help you figure out the correct size you need to get into the 0.3 to 0.8 mm range.



Mike

Makes sense... my idle was baaaad, which was why I was checking the shims in the first place.

Thanks.  That's my plan -test shim-, only now I can't get the shims out again because the bucket turned.  I would love to avoid taking the cam off, but that looks like where I'm headed... unless someone has a trick, or great idea?  Takers?

Any advice on taking off the cam, if not?   

Valves and buckets rotate as the engine turns over, they come up in a different place every time it stops.  If you don't have a tight bucket you can probably get the notch around to where you can get at it by cranking the engine.  Doesn't take too long even at cranking speed until you're overflowing oil out on the floor so be sure to pause the cranking while it drains down a bit.  Pull the plugs first so it cranks easy and fast.

False readings on swapping shims is due to oil float.
The valve being 1 size thick (aka 0 clearance measured when cold) will run like crap till its hot and even after its very very hot it will continue to run like crap at low revs.
2 sizes thick will be terrible even when hot and even with revs up.
Cool.
Buddha.

Quote from: gsJack on February 20, 2009, 10:01:06 AM
Valves and buckets rotate as the engine turns over, they come up in a different place every time it stops.  If you don't have a tight bucket you can probably get the notch around to where you can get at it by cranking the engine.  Doesn't take too long even at cranking speed until you're overflowing oil out on the floor so be sure to pause the cranking while it drains down a bit.  Pull the plugs first so it cranks easy and fast.

I thought so... I was wondering how I got the bucket turned around so I couldn't find the notch.