New to gs500's!

[timmah1991]

Hey guys, just bought a 1995 gs500e to be my commuting bike for this next year based on a bunch of positive reviews about the reliability and gas mileage. It runs a little off, so I decided to check the valves because everyone here seems to say that even having them a little bit off can cause a pretty big difference in the way it runs. Right side intake and exhaust were both at .05-.054mm so they were within spec. But the left cylinder intake was less than .04 (that was the smallest gauge I had so it might have been .03mm and I wouldnt have known) and the left exhaust was at .154mm. So I know that at least the exhaust shim needs replacing, but last night I forgot to measure the size of the shim :[ Is there any way to figure out what shim to get (approximately) without having to rip the head off again? It took like 5 hours and I really dont have a ton of time to dedicate to working on it. I'd rather just buy a few extra shims and use the one that works once I get it open again.



Thanks guys!
Thomas

[burning1]

There really is no way to measure the shims without removing them from the engine. If I were you, I'd line up a source of shims so that you could open the engine up, measure, and replace the shims in one go. While you're in there, I'd suggest pulling all 4 shims out. Measure them now, so that you don't need to measure them again in the future (handy if you're like me, and pull the cams rather than using the valve adjustment tool.)

I'd strongly advise you to open your exhaust valves up to .12mm. Doing so seems to make the valve clearances hold significantly longer - you might be able to increase your inspection interval to 8K+ miles going that route.

I can offer a small bit of hope... I've had 2 engines apart that were probably running on the factory original shims... Pretty much all the shims were in the 2.50 - 2.60 mm range. If you buy a few shims around that size (2.40, 2.45, 2.5, 2.55, 2.6) you might just luck out. Anyone else have comments?

No guarantee though.

[adidasguy]

If you were in Seattle, you could open up the engine.
Determine what shim you need.
Take out the existing shim.
Go to Aurora Suzuki and for $1 exchange it for a different size shim.
Go back home and put it in then close it up.

Your other choice might be take the bike to a reputable shop for a full tune up, check over and valve adjustment.

I do that when I buy a used bike. They can catch things I might miss and they have all the parts there. Worth the $100 + parts to me to get everything checked out: chain, bearings, brakes, filters, hoses, fluids, valves, etc. etc. etc.

[timmah1991]

Thanks for the responses guys! I acrually got the intake and exhaust measurements mixed up, for some reason i assumed the rear of the head was exhaust (probably gasoline fumes in the garage)

So my exhaust is sitting at less than .04 and intake is like .151

Tomorrow i will try to see if there are any suzuki dealerships in the area, anyone know of any good ones in chicago?

[tt_four]

If one is too tight and one is too loose maybe you'll get lucky and be able to switch them. I always check all of mine and see if any can just be swapped before I worry about replacing them.

Also, I know how much of a pain it is when the clearance is less than .04mm. I've searched forever and have not seen feeler gauges thinner than .038. Check and see if the bucket the shim sits in will still spin. If it spins that means there's at least some what of a gap, and you should hypothetically be able to just go one size thinner(shims come in increments of .05. Knowing your clearance is less than .04 and more than .00001 if the bucket spins, should mean that you can go one size thinner and know that you'll end up somewhere between .05001 and .089 and you'll be fine.

Also, don't worry about time as much, now that you've done it once you should be able to do it again in half of the time. Now that you know how things come apart and go back together you'll go much faster, and eventually you'll be able to do the whole thing in 45-60 minutes.

[timmah1991]

Alright. Yeah I suppose I could do it ALOT faster now compared to last time.

One quick question, would the valves being out of spec cause the bike to get like, terrible gas mileage?

Ive been getting like 30-35 mpg lately and I know I wont be getting 60 but somewhere closer would be much better.

Also, before the bike warms up completely, I have to give it throttle at stop lights to keep it from stalling out, will this be remedied as well?

The carbs have already been cleaned, but if these things are still causing issues after the valve job, I can try and clean them again I suppose

[burning1]

If the valves are *super* tight, you'll lose compression, which means a loss of power, which means more gas for the same performance. If your valves are simply on the tight end, without compromising compression, you'll get slightly more performance (more lift) at the cost of increased wear on the valves and seats (less contact, less cooling.)

Again, I'd advise you to run .04mm on the intake valves, and .12mm on the exhaust valves.

[gsJack]

...................I decided to check the valves because everyone here seems to say that even having them a little bit off can cause a pretty big difference in the way it runs..............

I never said that, wouldn't say that, and in fact I'd more likely say it would make little difference in how it runs unless they are really way, way off.  Don't be looking for a valve adjustment to fix your gas milage problem, look for a carb problem to fix that.  A used 95 GS500 most likely has been rejetted and who knows what other mods.  I got a steady 60 mpg day in and day out on my 97 GS for 80k miles and also get the same on my 02GS for 85k miles so far and expect to do so for 100k miles.  Never touched the carbs on either.

If you have cold compression you don't have a valve tight enough to affect how it runs and unless they are very noisy from being very loose you don't have one loose enough to matter much unless you throw a shim from redlinning it all day long.  A simple and quick finger in the hole compression check will confirm cold compression.  It does pay in the long run to check your valves regularly and keep them in or close to spec.  It's been my experience in over 160k GS500 miles on 2 bikes that intake valve clearances rarely if ever change and the exhaust valves get tighter with use as the valves recede into the seats.  Running the exhausts looser like burning1 suggested will definetly improve exhaust valve life.

http://img.photobucket.com/albums/v443/jcp8832/GSvalvelogs.jpg

[mister]

Check your valves on a Cold engine. That way all the metal has had a chance to get back to its resting size.

[timmah1991]

Thanks for all the responses guys, I've been riding every day and the milage seems to be about 35-40 ish. I got new plugs/ changed oil(mobile 1 full syn) and new oil filter today, and the left plug looked good, but the right cylinder seems to be running QUITE rich, (completely black plug) so I went back to auto zone to get a fuel line and check the float height, looks like the right carb is about a centimeter above the gasket. So I'm assuming that's the issue, and I just bought a spare set of carbs/rebuild kit so I'll be working on that at home whilst still riding the bike to work/school every day.

At this point, once I get the carbs rebuilt and installed, I might just have a mechanic do the valves for me, and have him set the exhaust a little looser like you said.


Thanks alot guys, you've been a big help
Thomas