What's the worst that can happen with loose valves?

[phire]

So, today I tore down the bike to do a valve adjustment. The intake valves are within factory specs, one of them is about .01 shy of being too tight and the other is about .01 shy of being too loose but never the less, still within specs. The exhaust valves are both about .04 and .04mm too loose and I was curious to know if I'm hurting anything mechanically by letting them go for a couple more weeks? I usually just drive it like a normal bike to and from work, no real racing or other abuse. Reason I've decided to let it go a couple more weeks if possible is because we're having our driveway redone and we won't be able to use it for about 2 weeks which means I'll have no garage space. However, if I'm going to end up slowly doing more damage by postponing the adjustment, I'll just do it out in the street if I have to.

If you're wondering why I just didn't finish it today.... well, I started it thinking there'd be at least one motorcycle shop or SOME auto store open to sell me shims and a valve shim tool... but of course, I forgot that it was Sunday and NO ONE is open around here on Sundays. Guess I should have been better prepared, eh? Even if I was, though, I'd still not been able to get any shims.

I know I've read this in other valve adjustment threads before, but, since we're this deep into the thread, what sort of things can you look for while under normal operation of the bike that would scream "DO A VALVE ADjUSTMENT, NOW!" ?


Oh, and all hail Kerry's Valve Adjustment video. 

I did have to laugh a few times when he was having problems with his shim tool.. It'd be full of suspense and anticipation, aaalmost got it alllllmost there   *POP* hehe, I would have been too scared to attempt it without it. I never realized just how easy it was before watching that video. Man, that thing should be published and sold in stores as a DVD Howto! I'd buy a few to support Kerry's efforts and to encourage him to do other videos.

[rangerbrown]

not sure, i am doing my first valve check tomarrow, after 15,000 miles should be interessting

[GeeP]

I wouldn't worry about it unless it's making a tapping noise.  Most mechanical valvetrain engines have tight valve clearances simply to keep valvetrain clatter down.  I assume you have been riding it like that for some time?  Another couple hundred miles won't hurt anything.  However, I suggest you make it a priority once your driveway is accessible again since they are technically out of specification.  

A marked reduction in power would tend to indicate that the valves are too tight.  Tapping on startup, or with a hot engine could signify loose valves.

[phire]

Slight tapping, yes. Don't ever really hear any "knocks". Occasionally when it's cold and being choked I'll hear a faint "knocking" if I move my head down to the side by the tank area. Very faint, though I have to really listen for it. And yes, you've assumed correctly, I have been riding it like this for some time... It's one thing to say to yourself "Ah, I'll check it next week..." Then, when you do and see how loose they are, it's more difficult to keep postponing it then.

[scratch]

So you have .12mm clearance on you exhaust valves?

The worst that could happen, not in your case, though, is you might spit a shim out from under the cam.

[phire]

So you have .12mm clearance on you exhaust valves?

The worst that could happen, not in your case, though, is you might spit a shim out from under the cam.

Yeah, about .12mm give or take a few thousanths.

So, just out of curiosity, what happens if a shim gets spit out? Then what kinda mechanical damage are we looking at?

[scratch]

Cam lobe gets nicely ground down on the corners of the shim bucket, those shavings in turn will probably grind away the smooth, hardened finish of the cam lobes.  But, let's not forget the big hole the shim will punch in your head (engine head).
http://gstwins.com/gsboard/index.php?topic=4728.msg37947#msg37947

[phire]

 

Hey, while I've got your attention, does Suzuki put the same shim size in all its valves from the factory or are they all specially fitted? Reason I'm asking is that I'm having troubles fishing the shim out of the bucket despite having the handy valve shim tool so if they're all the same then I can just run down to the store before they close and pick up the shims I need so when I finally DO get them out sometime tonight (hopefully) then I won't have to wait until tomorrow to finish.

[rangerbrown]

my little bastards got stuck, used the twessers and a srew driver to remove them, took about a hour start to finish read my thread.

[phire]

my little bastards got stuck, used the twessers and a srew driver to remove them, took about a hour start to finish read my thread.

I went down to Advance Auto and bought myself a small pen sized magnetic pickup tool for $6.99 rated to pick up 3.5lbs. Not sure that it really will pick up that much but it worked never the less. I spent about 20 minutes fooling around with 1 exhaust valve before I realized that both exhaust valves were fine based on my measurements I took...  So, with a little jiggling for about a minute or so I managed to pop out the intake shims fairly easily with this tool. Almost like the one Kerry used in his video. So, now that I know they're all 260's...... A little too late to get the job done tonight but oh well.

[rangerbrown]

yea i had one, but could find. the truck is down so i was sol.

[scratch]

Hey, while I've got your attention, does Suzuki put the same shim size in all its valves from the factory or are they all specially fitted? Reason I'm asking is that I'm having troubles fishing the shim out of the bucket despite having the handy valve shim tool so if they're all the same then I can just run down to the store before they close and pick up the shims I need so when I finally DO get them out sometime tonight (hopefully) then I won't have to wait until tomorrow to finish.

No.  When they assemble, they do a valve clearance check.  Snopyro, had 260's in three of his.

[runsilent]

Did my valves today too on the 02 GS, do them about every 8k miles.

I-2 was changed from .004 to .002" clearance
E-2 was left at .004"
I-1 was left at .003
E-1 was changed from approx .001 to .005"

I put 80k miles on a 97 GS and the shims were never changed on the 2 intake valves and both are still to spec.  Both exhaust valves were reshimed and one was down to the min shim thickness at 80k miles, the other about half way there.  The exhaust valves always changed to tighter and were down to min or no clearance at adjustment time.  Valves were receeding into the seats.

So I set my intakes to spec and tend to leave the exhaust valves on the loose side, they'll be tight soon enough.    If I had the right size shim on hand I'd have changed that .005 to .003" on the E-1, but was not concerned enough with the .005 to go get another shim.  I'll check them again next spring.

[Mandres]

[phire]

Well, I mistyped in my original post, it's my intakes that are loose. One is loose by .02mm from the .08mm max clearance and the other is .04mm off. I wonder if I should bring them down to say .05 all around? Or just bring them back down to the nearest shim I can get that's within spec and call it a day? I'm not sure if it makes any difference in anything when they're in the .03 - .08 specifications.