Valve clearance question

[sveach]

I did a long overdue valve check last night. What I found was left exhaust unable to spin shim/bucket, right exhaust and right intake less than .04 clearance but able to spin bucket freely.

My left and right exhaust were both 275 shims. My right intake is 260. I moved my 260 under the right exhaust and it now has approx .13mm clearance. Is this too much? I'm thinking I will move the 260 to my left exhaust, since that one was tighter. But my end goal is to have the exhausts be very loose, as I want this bike to last as long as possible. I just need to know if .13mm is too much clearance.

[DaielHancock]

your left exhaust bucket wont spin, but all the others will? First you have to get the notches on the ring hand end of the cam shafts to face towards each other, then do the right ex, and both intake valve checks, then rotate the engine so the notches in the right hand end of the camshafts face oposite ways, then the left exhaust bucket should spin, take the valve clearance then. Also i think the clearances are meant to be betwene 0.03 and 0.08 so yeah 0.13 seems a bit large.

[sveach]

I know how to do the valve check...I did it about 6000 miles ago and the left exhaust was tight, but within specs. So I am confident that the valve has just receded enough that it's too tight to spin. I know that when you're able to measure the intakes and the right exhaust, that the left exhaust is being pushed down by the cam lobe. I measured each valve with the cam lobe pointing straight away from the valve.

I'm planning on redoing the measurements again this morning, but I am confident that it is just really tight. The bike is running like crap once it gets hot and I have a hard time keeping up at highway speeds when it gets windy.

Also - GSJack (and I think a few others) are recommending that you leave the exhausts with higher clearance than factory, to extend the life of the head/engine. GSJack has recommended .1 clearance, so I'm just curious if .13 is too much. I'm going to move the 260 shim to the left exhaust valve and I'm hoping that it will bring the clearance closer to .1, then I'll order a different shim for the right exhaust and right intake.

[DaielHancock]

yeah sorry didnt mean to insult you there. i not really sure if 0.13 is to much then, should be better than no clearance ey.

[gsJack]

Actually I set my exhaust valves to .003-.005" (.08-.13mm) now.  On my last valve check a couple months ago I found my #1 exhaust to be .003" the max standard clearance and my min standard and I changed the shim to give .005" clearance.  The inch/mm conversions aren't exact, I'd leave that exhaust valve of yours at the .13mm with the 260 shim you have for it.

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

I set, actually leave, my intake valves at the Suzuki .001-.003" spec, they never seem to change while the exhaust get tighter for me.

I'm planning on redoing the measurements again this morning, but I am confident that it is just really tight. The bike is running like crap once it gets hot and I have a hard time keeping up at highway speeds when it gets windy.

Valve clearances increase as the engine warms so it should run better hot than cold if valves are the problem, anyway you need to get the valves right first.

[Revised exhaust valve spec from .08-.12 to .08-.13mm]

[sveach]

yeah sorry didnt mean to insult you there. i not really sure if 0.13 is to much then, should be better than no clearance ey.

Not insulted, don't worry. 

GsJack - good point on the valves increasing when hot. Not sure then. Maybe it's just in my head, but whether cold/hot the bike definitely isn't running as well as it used to. We'll see what happens once I get the valves back where they should be.

I'm going to put my 260 shim on the other exhaust valve just so i can measure it. Then I'll order the shim needed for the exhaust and the intake that are too tight.

Thanks for the input on keeping the exhaust at .13mm.

[sveach]

Just reminding myself. Need a 260 shim for right exhaust, 255 shim for right intake.

Swapped my 260 shim to the left exhaust and its about the same as the right, .13mm clearance. So I'm leaving my exhausts on the wide side of clearance which makes me feel better. One of the local shop owners said he might have the shims I need so I will be giving him a call in the morning. Fingers crossed!

[Allen]

Yeah, the bucket won't spin eh? Nice.  I had to go down 4 sizes from 275 to 255 to get it within spec. I'd try a 265 for the right ex, down two sizes sounds about right.  You can try the 260 and see if ya like it or not but its alot of work to get back in there.  If the intake was fine, I'd leave those alone and fix only the ex.

[Allen]

Make sure ya match the shim diameter to your old one. There is another japanes manufacturer's size that is just .5 mm smaller. It looks almost the same diameter but its not.

[sveach]

I was explicit in saying I needed 29.5 mm shims. Either way, I'm taking both my 275 shims with me to give to the shop in exchange for these. I'll make sure I match them up and be sure they're not 29 mm.

[crzydood17]

wasn't kerry messing around with shims that weren't the right diameter to see if they helped oil flow? anything ever come from that?

[burning1]

I wouldn't recommend running the 29mm shims in a GS500. I've heard stories of the GS throwing the shims, and IMO running the wrong size is begging for that to happen.

Agree completely with what gsJack said - based on his advise I ran .08-.13mm on the exhaust side my race bike, and never experienced an issue. On the intake side, stick to .03-.08 -- smaller clearances mean more lift and better performance.

[sveach]

I'm definitely not going to run smaller shims on my bike. The local shop here offered to just trade me shims! Can't beat that. I'm taking my 2 275 shims up and we're going to mic them, and get ones that are about .08mm smaller.

This is probably the wrong crowd to tell, but if you ever need something for a Busa or anything performance - talk to Smithers Customs! http://www.smitherscustoms.com/

These guys host a free bbq the first tuesday of every month. All you can eat burgers and hot dogs, chips and soda. Hard to beat that!

[ben2go]

I get all my valve shims right here.They have never failed to deliver exactly what I order.
http://crc2onlinecatalog.com/valve_shims.htm

[sveach]

I get all my valve shims right here.They have never failed to deliver exactly what I order.
http://crc2onlinecatalog.com/valve_shims.htm

I have that link saved and I'm going to order another shim from them come winter. The local shop had what I needed for the intake, but they didn't have the 260 or 265 I wanted for the exhaust, so I'm using a 270 right now. Gives me clearance but not as much as I'd like.