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Crf 250r wont start after valve adjustment


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i took my 2005 crf 250r in for a valve adjustment an when it was done it was hard to start at first and then i rode it for 1 tank of gas and it got harder to start at the end. The next day it wouldnt start at all ive kicked it a lot and it backfires most of the time and it is cold but i figured i would still be able to start it.  any ideas why it doesnt start?

Edited by Cjerz
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Who did the work??? A shop, or a friend?

- Cam timing off a tooth

- Valve clearances too small or non-existent

- The cam chain auto-tensioner wasn't (properly) retracted during its assembly process

- Make sure MIL light doesn't start blinking after starting it

- Spark plug ceramic broken, coil wire arcing or some other wiring is loose or disconnected

Measure all four (4) valve clearances and report them back, here... also check cam timing by using the left-side flywheel marks to verify piston TDC.

Edited by Eddie8v
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What Eddie said - except the MIL light. That only applies to FI bikes (2010 and up).

 

My money is on the valve clearance being off. That - or it could just be coincidental that you are losing compression. Ask the shop if they did a leak down test. 

yeah it doesn't really have that much compression. I just brought it in for valve adjustment thought how could it be valve clearence

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There are 4 things to measure, not just 2. I think you're effin with us...

Lol both exhaust are .006 and both intake are .005 I thought that would kinda be common sense Edited by Cjerz
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Lol both exhaust are .006 and both intake are .005 I thought that would kinda be common sense

And those clearances sound "ok" to you? Do you know what they should be? Sounds like your exhaust valves are too tight. And do you need to also measure the decomp clearance on that motor? Edited by Eddie8v
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And those clearances sound "ok" to you? Do you know what they should be? Sounds like your exhaust valves are too tight. And do you need to also measure the decomp clearance on that motor?

could it possibly have something to do with the decompression lever like it is stuck or something? because it has barley any compression and when i kick it while holding the decompression lever it feels the same if im not holding it

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could it possibly have something to do with the decompression lever like it is stuck or something? because it has barley any compression and when i kick it while holding the decompression lever it feels the same if im not holding it

Your exhaust clearance is too tight, and I don't know where your decomp clearance is, either. So, my guess is your exhaust valves aren't sealing fully when they should (tight clearance and tight decomp, perhaps, too) causing your issues.

Edited by Eddie8v
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