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Valve shim adjustment on Gen 1 KLR650

ntklr650

Matt6:34
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Krum Tx
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Michael
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M
I already posted this question on the KLR650 thread but wanted to put it on here as well. I just pulled my shims last night on my 2001 KLR650 and here are my results.

  1. Should I aim for the center of the range or leave anything on the high side that's still in range where it is?
  2. Is there anything wrong with reusing old shims that are in good shape or should I order all new shims?
image.png
 
I would do all four. Better a little on the loose side and still be in spec. Change the left exhaust to 2.35 for a clearance of 0.23. You can reuse old shims, they are extremely hard and wear very little. There is not much friction to wear them. If you get your shims from a shop that has been in business for a long time, they may have half size shims to get them all to right in the middle. I know the parts diagram does not list half sizes, but lots of bikes come from the factory with half sizes.
 
Valve spec is just that. Anywhere in the range is just fine. Most clearances tighten over time (not always). If that is the case with your bike, then it is best to be on the loose side when all shimmed up. Never did get the whole deal about being in the middle of the spec like that was something good. Makes no difference. Either it is in the specified range or not. Shims can wear but not under usual circumstances. Measure them up to confirm what they are and reuse.
 
Johnf3 is right about being in spec is OK, but if you don't check them on a regular basis, loose is better than tight. When I raced, I set my intake to the tight side so it would open slightly earlier and close slightly later. I checked my valves after every weekend.
 
This is the first time i have done this on this bike and i have ridden about 15K miles. Im not sure if they have worn tight or loose since i am on the high side on all of them.
 
I’ve got over 80K miles on my’97 KLR, checked the valve clearance twice since new, changed two shims at 50K because they were too loose. Set them on the high side of specs (cause that’s how I was taught).
Just my 2 cents, but I would put the original shims back were they were. Good Luck, Bud…
 
I checked mine at 12 K, all ok, again at about 30? And then I rode with a certified mechanic (TWT member) who told me that 1) If it starts every time quickly, don’t worry about the valves. 2) If it doesn’t backfire on decel, don’t worry about the valves. And three, if your fuel economy is not suffering horribly, don’t worry about the valves. As you know, I’m at 106K, I sealed the valve cover last year and didn’t check them. The bike starts right up, doesn’t backfire, and I recently got 46MPG coming back from Mena last week. Change the oil, don’t rev the snot out of it, and don’t worry to much about the valves if the machine is working correctly.
👍🏻
 
All I can say is wow to the longevity ya'll are achieving. That's killer. I think not revving the bikes hard really helps valve adjustment stay in check. Oil, and filters (air and oil) change keep things fresh and piston wear minimized. My guess is you both do all of this. My buddy in CO does all three of these things and has a 70K mile DR650, 78K DRZ400 and 245K mile 2005 BMW R1200GS. Well over 60% of these miles are off pavement. He's also made KLX300s go over 50K multiple times!
 
So I changed 2 of the 4 shims shown in green below. After the change, we rotated the engine a couple times and rechecked the clearance. From what we could tell we were right on the money as calculated.
image (1).png

We then proceeded to pull the carb for a light rebuild and took the following picture down the intake. Any concerns on the rust or anything else you see?
IMG_20221003_192752511.jpg
IMG_20221003_192851633_HDR.jpg
 
Nossir. Button it up and ride. 😊. Was something wrong with the carb? 🧐
 
Nossir. Button it up and ride. 😊. Was something wrong with the carb? 🧐
Had a little junk in the idle screw. I think that was the only issue all along. I am super surprised how clean everything was considering I rebuilt the carb over 6 years ago and 10k+ miles of cheapest fuels I could find.
Planning to button it up tonight and give it a test.
Thanks for your help on this little training session.
 
Had a little junk in the idle screw. I think that was the only issue all along. I am super surprised how clean everything was considering I rebuilt the carb over 6 years ago and 10k+ miles of cheapest fuels I could find.
Planning to button it up tonight and give it a test.
Thanks for your help on this little training session.
Michael, you did all the good! Go man go!
 
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