do I have a bent valve?

I'm in the middle of a 93 VFR rebuild project. I'm putting a 96 VFR engine in the frame. I was checking valve clearance and just about every darn valve was within spec at 36,000 miles. Except one of the cylinder 2 exhaust valves was WAY too loose. The shim already in under the bucket was .205. it was so loose, I couldn't get a guage thick enough to even measure. I cycled the pistons several times and rechecked. Same results.

So, I put in a .350 in, and it was still a little loose but better. That was the thickest shim I had. The only think I could think of was the valve was just a bit bent and wasn't "seating" all the way down. Does this sound it might be?

As soon as I get the time, I'll try to test the compression.

Any input appreciated.

 

It does sound like something (bent valve, carbon or sand on the seat, etc) is it holding the valve open. Was the motor from a salvage yard or been in an accident? If the exhaust pipes are off maybe you can do a visual, but a compression check of that cylinder before anything else.

So if it's debris and it clears, then the thick shim will be holding the valve open. If bent, then compression fails even with thin/no shim.

 

Thanks for the offer. I have a second motor with about 70,000 miles on it from a 93 I can use for parts. Just about everything is interchangeable between the gen 3 and gen 4.

The donor bike is a no-title low sided bike without much structural damage but left for dead at a salvage yard. Turned over and ran just fine. Even rode the bike but I know an engine can run acceptably with a single bad valve.

I was just hoping for that last nugget of knowledge that told me it was OK and that the heads wouldn't likely need to be removed. But deep down inside, I know I'll be taking the heads off. Oh well, was hoping not to spend the $200 on a gasket kit but I probably will be doing so. But compression test first......

 

You could also do a leakdown test.