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Kritter

Valve check/adjustment

14 posts in this topic

I just adjusted the valves for the first time ever on an XR650 and I would rather shim any current 4 stroke motocross bike any day of the week then have to deal with the limited space on the 650. I can remove the cam assembly, shim and put back togehter in about 30 minutes on my 450...

the 650 took me that long to just get top dead center looking through that little peep hole with a mirror while kicking it over, I finally got it close enough then put it in gear and rocked the tire back and forth until it was dead nuts. Talk about a PIA. I tried taking my side case cover off but the skidplate was in the way and that is as much a PIA to re-install as was the exhaust valves to adjust!

I am going to keep the valve checks on the pig at the current interval...1500 miles! I would rather split the case or change 30 tires then deal with that again!

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Make you a deal . You shim my bikes and keep my footpegs fixed ,and I'll adj. your 650 :ride: I've split lots of cases and adjusted alot of ktm's and xr's , but never shimed a bike.

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...then put it in gear and rocked the tire back and forth until it was dead nuts...

Kris, if by chance the rear wheel rocks back far enough in the non-drive direction, the auto decomp mechanism might kick in and lift one of the valves and mess up your check. Hopefully that's not the case, but if by chance you found that one of the valves was much father out of spec than the others and you also experience more rattle in the engine than normal, then perhaps the auto decomp mechanism kicked in and messed things up for you while checking / adjusting your valves.

Hopefully it's all good to go for another 1,500+ miles :ride:

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You sound like drama queen! The valve adj isnt that difficult. I just did mine for the first time one week ago!

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I find it easier to take the left engine cover off and remove the spark plug. Then I use a socket and rachet to turn the engine over (more control than using the kick starter). It gets easier every time - like mounting tires. With the larger valve covers on the 650R it quite a bit easier than on the RFVC engines.

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Kris, if by chance the rear wheel rocks back far enough in the non-drive direction, the auto decomp mechanism might kick in and lift one of the valves and mess up your check. Hopefully that's not the case, but if by chance you found that one of the valves was much father out of spec than the others and you also experience more rattle in the engine than normal, then perhaps the auto decomp mechanism kicked in and messed things up for you while checking / adjusting your valves.

Hopefully it's all good to go for another 1,500+ miles :ride:

dam the right side exh valve was out quite a bit...guess I will double check. Bike wont be together to be able to start for a couple days as I prep for prerunning so I cant start it and listen so I will just go back and do it again, this time taking the skid plate and side cover off.

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Make you a deal . You shim my bikes and keep my footpegs fixed ,and I'll adj. your 650 :ride: I've split lots of cases and adjusted alot of ktm's and xr's , but never shimed a bike.

Bring it over...ive got the shims and can show you the speed tips!

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dam the right side exh valve was out quite a bit... .

Sounds like the auto decompressor was enaged when you adjusted the valves. To make sure the auto decompressor is not engaged, use the kickstarter until you feel compression, (you might have to turn the engine over a few times to get compression) then turn the engine with the flywheel bolt to align the "T" mark, then check the clearances.

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DUDE The 650r is one of the easiest bikes Ive ever worked on, I have the motion pro tappet adjusters and it only takes me about 20 minutes to do my valves, thats no shit man :ride:

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dam the right side exh valve was out quite a bit...guess I will double check. Bike wont be together to be able to start for a couple days as I prep for prerunning so I cant start it and listen so I will just go back and do it again, this time taking the skid plate and side cover off.
Hey Kritter, Thanks for the peg mod. Love it!

If you take the side cover off, be sure you have a gasket to replace the one you will probably destroy. I’m gonna oil one side the next time so I’ll have a better shot at saving it.

What ever you do, don’t go back if you miss TDC or you actuate the auto decompress, not even ‘a smidge’. If ya miss it then just go around twice more. The auto decompress works when the engine reverses rotation and it doesn’t take much... Just go real slow when you’re coming to the mark.

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I pull the seat and tank, take out the spark plug, put it in gear, and use the rear wheel to rotate the engine forward while looking through the inspection hole. I never take off the side cover. Like the others said, do not let the engine turn back or you'll get a false reading. Very easy, 20 min job.

Peter

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Im glad you guys told me about the valve being out from rocking the tire...checked it again and sure enough the valve that I adjusted that was way out of whack was way out of whack after I did the TDC with the flywheel rather then the tire.

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