About to do my first valve clearence check. Anyone know the size of the o-rings?

[Toner]

Been watching the videos of the guys doing this and I think I have bought all the tools and things to get cracking at it today.

I bought the main valve cover gasket but forgot about the o-rings used with the screws to screw the cover down.

Anyone know a size for them. I have a box of o-rings here but I would like to go and pick up some more before I start this job if I need them. Don't have any other mode of transport.

They are the ones that go here:



Many thanks to the guys who put up two vids too which show you how to do this job. 
Would not be able to attempt this otherwise. 
https://www.youtube.com/watch?v=jIL0eMzRPF8 
https://www.youtube.com/watch?v=Qgm4dwy0TJ4 

I don't have replacement shims but I'm going to check the sizes I need.

[gsJack]

I did over 20 valve checks on my 97 and 02 GSs without ever changing those o-rings on the 6 valve cover hold down screws and without ever having one leak.  My 02 sits in the garage now with over 100k miles on it with the ones installed at the factory.

[Toner]

good to know and I wouldn't be worried about them unless henry Chen in the second video I posted discovered one of his needed replacing when doing his video. 
Might just risk it or pick up some more at the store so I have a few more sizes as I realised I need to get some gasket sealant anyway.

[Toner]

just took the valve cover off. 

Doesn't look like there were any o-rings on the screws.
I guess either they dissolved completely and no-one has ever had this off or it was put back on without any before.

I'm going to go with some snug ones on the thin side unless anyone has any other recommendation. 

[Toner]

false alarm. They were still in the cover. All of them.

Look a bit flatter than anything I have, not sure if they have to be exact or anything.
I've got some that squeeze in  but are thicker and some that are looser but about the same thickness.

They measure about 23mm on the outside diameter and 19mm on the inside.

Suppose I'll just re-use them.

[Big Rich]

Good idea to just reuse them. I don't know what the stock ones are made from, but normal rubber orings might not be able to handle the heat from the cylinder head. Might be good to order some for next time though.

[yamahonkawazuki]

I did over 20 valve checks on my 97 and 02 GSs without ever changing those o-rings on the 6 valve cover hold down screws and without ever having one leak.  My 02 sits in the garage now with over 100k miles on it with the ones installed at the factory.

this guy knows his b stuff

[sledge]

I would treat the statement as an observation, nothing else.

[ragecage23]

I just did a valve adjustment and reused both o-rings and the head gasket. BaltimoreGS said, "if they're still soft and pliable you can reuse them. If they're dry and cracking replace them." I followed that advise and I don't have any leaks.

[Toner]

just finished valve checking.

Wow, that was the hardest job on my bike so far.


Looks like it took me about six hours with breaks. I had to keep watching the vids to make sure I was doing everything right.

That shim tool is no fun at all but I eventually got the hang of it.

Something that is not explicitly mentioned anywhere is which side to insert the tool. 
It's on the inside in case anyone is wondering, for all valves. 
And you pull the shim out that side too with the magnet.

Some of the shims were hard to pop up with a little screwdriver but you just keep trying. 
If you can rotate them, you know the shim tool is not pressing down on the shim itself and you just have to keep struggling.

Something I was not prepared for was what a nuisance it was going to be to seat a new gasket.
Kept slipping out when I went to put the valve cover back on. 
Maybe I wasn't using enough gasket sealant so I eventually squeezed a good bit on into the groove and just took it really carefully. 
When you are trying to seat it, a little bit of the gasket will pop-up somewhere. You push that down and a little bit will pop up somewhere else...like wack-a-mole.

There must be a better bike design out there that makes this job easier. 
Especially as they recommend doing it every 4000 miles. 
That's about twice a year by my count.
Are all Bikes likes this or are there other methods?

A couple of more things I learned.

I need some more feeler gauges.

I had a:
.127
.102
.076
and then more above and below which I did not need.
I had no .08 or .09 which I could have used.
That was disappointing as I bought a fairly big set.

I need a better micrometer.
Mine goes to one decimal place. 
You need one that goes to two.
I could not accurately measure my shims.

So here are the measurements I took:

L Intake
.076 fits.
.102  does not fit.
shim was marked 250. My micrometer measured it at 2.4 mm (remember it only shows 1 decimal place)

R Intake
.076 fits.
.102  does not fit.
shim was marked 255. My micrometer measured it at 2.4 mm

L Exhaust
.076 fits.
.102  fits.
.127 does not fit.
shim was marked 260. My micrometer measured it at 2.5 mm

R Exhaust
.076 fits.
.102  does not fit.
shim was marked 265. My micrometer measured it at 2.6 mm

So what do you think? 
Three of them had a gap between .076 and .102
One exhaust valve had a gap between .102 and .127

I know the range is supposed to be .03 - .08.
Maybe three of them are around .08 or a little higher. Is that ok you think?

[Big Rich]

A "little" higher than .08 is ok, because valves generally get tighter with mileage. I'm not saying don't check them for the next 30k or anything though. Speaking of which, that every 4k miles interval..... is a good thing but don't expect to change shims every 4k miles. You might pop the cover off, run some gauges under, and then bolt the cover back on.

One suggestion though: write down (or remember where you posted) the current size shims and clearances. That way when your next valve check rolls around you can note what size shims you "might" need.

[Toner]

Thanks Rich,

Does that same advice apply to that one exhaust that had a gap between .102 and .127?

Should I be overly concerned about it?

[Big Rich]

Meh.... I can't say that it is "ok" with any degree of certainty. The actual clearance might be .104, which I wouldn't be afraid to run. But it also might be be on the other end.....

Really, it's your engine and your decision. I would dive back in on my next opportunity and try another shim.

[Toner]

Thinking about getting a 250 and and a 255 shim.
Do you think that would be ok?

Reasoning is: 

Say the shim does measure 26.0 and my micrometer is junk.
The clearance was between 1.02 and 1.27

need a clearance of between .03 and .08
1.02 - .03 = 99

So If I get a shim that is 25.0 that will get me to .03 clearance if the current shim is 260 and the clearance is on the low-side of 1.02 and 1.27.

Then I also buy 25.5 shim that will get me to .07 clearance under the same criteria and give me an option if the clearance is on the high-side.

[gsJack]

They all look good to me I wouldn't change any shims.  I set exhaust valves at .003-.005" (.08-.13mm), Suzuki .001-.003" spec is too tight for exhaust valves for long life.

[Toner]

sounds good to me Jack.

[prmas]

For future reference for anyone who needs it, the "O" rings are 1.9mm thick and 14.5mm ID.

Macka

[ragecage23]

Toner, not sure if you already know this, but put the shims in so the number is facing down. Then the numbers don't get worn away. When I did mine I ran the exhaust valves to .1 clearance and the intake to .8

[Toner]

Welp, I did the valve clearance check again.
Wasn't any easier getting those shims out 
Bought a proper mechanical vernier caliper to get two decimal places this time.
Here are my measurements:



................................
exhaust - top left (Stamped 2.60mm | Measured 2.66mm)
valve clearence: .09 - .1mm

exhaust - top right (Stamped 2.65mm | Measured 2.66mm)
valve clearence: .09 - .1mm

intake  bottom left (Stamped 2.50mm | Measured 2.52mm)
valve clearence: .08 - .09mm

intake bottom right (Stamped 2.55mm | Measured 2.56mm)
valve clearence: .08 - .09mm
.........................................

Hoping to get some help with a couple of questions. 

Three of the shims measured roughly the size which was stamped out them  (within .01 — .02 mm). 
Perhaps this is due to the accuracy of my caliper as it is listed as having a +/- 0.02mm accuracy rating.
.02mm is the smallest increment. 

But the left exhaust shim was stamped 2.60mm but measured 2.66.
Does that sound right? Is it possible the shim expanded?
Perhaps it was stamped in error?

I measured the clearance in the two intake valves as .08
A .09 feeler gauge leaf would not fit in either. The .08 leaf would. 
This seems to be just in spec as the Haynes manual says the clearance has to be between .03 and .08mm.

For the exhaust valves, the clearance was .09mm.
A .1mm feeler gauge leaf would not fit but the .09mm leaf would in both. 

Before someone on here suggested running the exhaust valves at .1
BaltimoreGS say that's fine too in this vid: 
https://www.youtube.com/watch?v=jIL0eMzRPF8

You think .09 is good enough or should I get new shims? 
If my measurements are correct and If I am reading the shim size table in the Haynes manual correctly I could get two 2.70 shims for each exhaust valve. 
Does that make sense. Have I done the calculations right?

[sledge]

To answer the original question.....

14.5mm ID, 1.9mm thick.