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Main Area => General GS500 Discussion => Topic started by: Knuttzz on August 01, 2016, 05:38:14 PM

Title: One last stupid valve question
Post by: Knuttzz on August 01, 2016, 05:38:14 PM
So measured the valves this evening. All I could find was a feeler guage set that went down to .04 mm.

The right intake was .06mm
Right exhaust I couldn't even get the .04mm in it.
Both valve son left side wouldn't accept the .04mm shim.

I know this isn't in spec at least for 3 of them but are these numbers somewhat normal for an engine with approx 20k miles?

It would seem to make sense cause lately I've noted a loss of power once it's thourougly warmed up.
Title: Re: One last stupid valve question
Post by: HPP8140 on August 01, 2016, 07:01:54 PM
Yes, according to service manual valves are to be checked ~4k miles
Title: Re: One last stupid valve question
Post by: Knuttzz on August 01, 2016, 07:07:55 PM
I don't know if they've ever been checked or adjusted before. When I sorta inherited the bike it had 18k on it and seemed to run fine.
Title: Re: One last stupid valve question
Post by: user11235813 on August 02, 2016, 06:45:41 PM
Quote from: Knuttzz on August 01, 2016, 05:38:14 PM

I know this isn't in spec at least for 3 of them...

But you don't know that because you do not have a feeler gauge less than .04mm. Seeing as the spec is .03 -.08 it is quite possible that a .03 will fit.

I finally got around to checking mine after 26,000kms and the intakes were .06 and the exhausts were .05 which made me feel a lot better. It's such a pita to strip the bike down to get to the valves that one wonders why not have a feeler ready? Also for your own peace of mind, surely it would be better to strip it down again and check the valves properly so at least you can know if they are on their spec limit, or actually doing damage to the valves.
Title: Re: One last stupid valve question
Post by: Knuttzz on August 02, 2016, 06:49:14 PM
Well considering I can't move the shim in those three I'd say at the very least they are rubbing the cam. And there is no way I'm gonna leave the clearance at .03 mm. Even if that's what they were I'd want a little more for peace of mind. It's nothing a surface grinder can't fix.
Title: Re: One last stupid valve question
Post by: HPP8140 on August 03, 2016, 04:16:26 PM
Quote from: Knuttzz on August 01, 2016, 07:07:55 PM
I don't know if they've ever been checked or adjusted before. When I sorta inherited the bike it had 18k on it and seemed to run fine.

Yeah, many get caught out by valves on this bike. It will run fine when warmed, but some damage is being done. Bought 2 bikes with the left exhaust being tight (no clearance) and that valve was never the same. Wore much faster than the others.
Title: Re: One last stupid valve question
Post by: Knuttzz on August 04, 2016, 05:56:23 PM
Yeah I can easily how one would get caught out on valve adjustments, this bike has the shortest intervals between valve checks of any bike I've owned.

I finally got it back together today. Both intakes set at .06mm and both exhaust set a loose .08 mm.

It took me a while cause I kept tweaking the shims on the surface grinder to get the clearance I wanted.

Bike does seem to run better. Last time I rode it I could feel a loss of power when accelerating from around 65mph in 6th gear. Hell it would even lose speed climbing hills at 70-75 on the highway.

Today the same hill it would lose speed on the bike accelerated and gain speed fairly good.
Title: Re: One last stupid valve question
Post by: W201028 on August 07, 2016, 06:10:48 AM
+1 on grinding shims. That is an economical way to keep riding