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valve shim size

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checked my valve clearances, one was slightly out of spec. 

 

I thought I would be able to just buy a shim with a "stock shim size", swap it for the current one

...and I would be good to go. Does it not work like that?

 

Whats is the shim diameter for the 09 KLX-250s?

How do I figure out required thickness? 

 

Im not with the bike or the notes I took and can't remember if it was intake or exhaust.

I want to avoid opening up the valvetrain and having it sit there till I get the shim.

I was hoping I could just get the shim first then take it apart and put it together within the day.

 

 

Edited by horrorfan

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I am going to guess that your clearance is larger than it should be. Since you have the measurement go to your local bike shop and give them the information and they should be able to sell you the right size shim to get you back in tolerance. Then you take it apart, change out the shim, and put it back together. It really is not to terribly tough to do but you have to remove the camshaft to remove the bucket that the shim sets under. The trick is to do all this and put it back together without loosing your cam timing. 

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If you dont have a micrometer you can get one at Home Depot for 30 bucks. It measures thickness. Im assuming you have feeler gauges if you know its out of spec. It will save you headache if you buy a shim kit. If the clearance is too tight remove the shim and measure it. To loosen the clearance use a smaller shim. Thus increasing the room between the shim and rocker arm. To tighten it use a bigger shim. Its better to be loose than tight. It takes the math out of it when you have a kit. Lets say you are too tight. The micrometer measured you shim at 2.24. The next size down in the kit is 2.20. Put that in and check it. If its in spec good if that is too loose. Then get a 2.22 from the shop. Bc the kit comes in. 04 increments. Let me know if you need anything else. Also watch a you tube video they will explain the math.

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4 hours ago, KAWBOYBILL said:

I am going to guess that your clearance is larger than it should be. Since you have the measurement go to your local bike shop and give them the information and they should be able to sell you the right size shim to get you back in tolerance. Then you take it apart, change out the shim, and put it back together. It really is not to terribly tough to do but you have to remove the camshaft to remove the bucket that the shim sets under. The trick is to do all this and put it back together without loosing your cam timing. 

I already called and told them my bike model and engine size. They told me they need the exact shim size. (diam and thickness)

..thats why I'm on here asking, I know how to reset the timing and put everything back together I just need to figure out what shim size.

 

the current one I'm pretty sure was 0.10mm out of spec and you're right it was larger. The bike is all put together right now but I will measure it again when I take it apart next week. I just want to be sure I know how to buy the right shim so I can replace it if it is. 

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4 hours ago, dirtbikedaddy said:

If you dont have a micrometer you can get one at Home Depot for 30 bucks. It measures thickness. Im assuming you have feeler gauges if you know its out of spec. It will save you headache if you buy a shim kit. If the clearance is too tight remove the shim and measure it. To loosen the clearance use a smaller shim. Thus increasing the room between the shim and rocker arm. To tighten it use a bigger shim. Its better to be loose than tight. It takes the math out of it when you have a kit. Lets say you are too tight. The micrometer measured you shim at 2.24. The next size down in the kit is 2.20. Put that in and check it. If its in spec good if that is too loose. Then get a 2.22 from the shop. Bc the kit comes in. 04 increments. Let me know if you need anything else. Also watch a you tube video they will explain the math.

I already got calipers. just need to know what to do with them haha...

I thought about buying the kit but its about $100 more than what I want to spend. 

 

I think what I get it. So if I check the current one say its

the gap is 0.10 mm too big.

I need a AT LEAST 0.10mm thicker shim to close that 0.10 gap? 

 

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Better take your calipers with you. If your repair shop is anything like mine you will end up doing most of the work. In my case they just set a box on the counter and said "find the one you want". If you end up in that situation make sure you mic the circumference also. 

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32 minutes ago, KAWBOYBILL said:

Better take your calipers with you. If your repair shop is anything like mine you will end up doing most of the work. In my case they just set a box on the counter and said "find the one you want". If you end up in that situation make sure you mic the circumference also. 

...the guys at the shop are usually pretty helpful.  Thats a good a idea, the shop is all the way downtown ...I don't want to travel there for the wrong shim. I was going to bring the old shim but bringing the calipers sounds like a good idea.  thx

 

do you know if there are certain shim materials that last longer or are "higher quality"?

Edited by horrorfan

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7 hours ago, dirtbikedaddy said:

Its not the shim that wears out its the valves and valve seats. But its normal wear and tear.

gotcha ... thanks

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