78 GS550E valve clearance problem

[dtkeith]

The bike ran fine before I tore into it over the winter, I would think if it had a bent valve, it wouldn't run and rev well?

[tkent02]

Does it still run fine? How is the compression?

[dtkeith]

I'm not sure if it still runs fine, I haven't tried running it since I took the cam cover off. I also haven't tested compression, what is the process for this?

[Eli69]

to test compression you need something like this tool:

http://www.walmart.com/ip/Equus-3612-Innova-Compression-Tester/14644667

attach it to plug hole, turn over engine w/ throttle wide open. check reading. if it's low ya know somethings wrong. should be >100psi, then, add a couple squirts of oil to cylinder and repeat. compare to previous measurement. a large increase in pressure usually means bad rings, small change means a valve problem.

so if there is a small difference in dry and wet tests then that valve may not be closing.

don't know if this will help but that's the way i'd play it i think.

[Flyboy]

Just pull the cam and quit monkeying around, I pulled both my cams, swapped a few shims around to get all my clearances in spec and put the cams back in, had the valve cover buttoned up in inside of an hour for the whole job, as Tom says, it really is no biggie, sounds more daunting than it is.
Even if compression is low, you won't know if it is the valve that is bent or the bucket sticking and holding the valve off it's seat, so what you gonna learn from it, other than what you already know, you have a problem.
Even if the valve is closing fully, with a huge gap like that the valve is getting nowhere near its full lift off the seat, so compression will be low anyway.

[Maddevill]

Like I've said before, you may have a bike running on 3 cylinders and just don't know better because you've never heard it running on 4. A leak down on that cylinder will tell you right away whether you have a valve problem, a ring problem or something else.

[dtkeith]

Alright everyone, I ran into some free time yesterday, and tore it down. I stripped the engine down to the block (pistons exposed). The valves looked fine on a visual inspection.. just a decent amount of carbon deposits on the valves and pistons. I think I am going to take it to a shop and have them look at it/diagnose.. I'm ready to get back to riding!

[Ghostgs1]

Why not pull the valves and clean it up, lap the valves lightly and reassemble it carefully. You should be able to get it working properly without using the dealer. That's the way I do it, just my opinion and suggestion. Ray

[dtkeith]

Because I honestly have no idea how to do that, don't have the tools, or the time. I know a couple local independent shops I can take it to that I trust who can get it done.

That being said, what is that process like/what tools would I need?

[cowboyup3371]

See the valve lapping document on Basscliff's site:

http://members.dslextreme.com/users/storagecliff1/images/HOW_TO_LAP_VALVES.pdf