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too much compression

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A friend of mine has a 05' CRF250R that has soo much compression we can hardly kick the bike. It is almost virtually impossible to kick start. We have to roll start it. I weigh 210lbs and even with me jumping on the kick start it wont budge at all untill after maybe jumping on it twice to get through the compression stroke. Whats the deal? I was thinking it could be an issue with the valve clearance however, after thinking about this all night I am really not certain. I just know it should not be this difficult to kick over. I have read about the CRF clicking sound when getting to TDC. I dont really know if we are hearing a clicking sound. WHile kicking it over when it gets to the compression stroke it almost sounds like as if the piston is getting to a point in the cylinder where its almost too tight to get through. Its hard to explain but it sounds like as if the piston is stopping midway through the cyclindar. Its the exact kinda sound my old bearings make in my swingarm linkage made when the lube dried up. Once the bike is pushed off and running it idles very well, and runs really great with alot of power. ANyone have an idea? We plan to check valve clearance but we really dont know if this is gonna be the problem or not. Is it possible the previous owner put in a high compression piston and are they really that HIGH in compression that a guy that weighs 210lbs cannot jump hard enough on the kicker to kick it over? ANy help would be greatly appreciated.

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Do you hear the click when you get to TDC, if not it could be a problem with the decompression lever, if thats not working you can hardly kick it over. Take off the valve cover and look and see if it's working when you kick it over.

For to much compression should not be the problem we used a 14 plus piston all last year and it is not that much harder to kick then a 13.5 we used in another bike.

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The stock cams wear in the area of the decompresor rod that contacts the roller so the decompresor becomes unefective .The area is machined flat when the decompresor rod is removed from the cam you will see an indentation in that flat area.

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The stock cams wear in the area of the decompresor rod that contacts the roller so the decompresor becomes unefective .The area is machined flat when the decompresor rod is removed from the cam you will see an indentation in that flat area.

And if this is the case, get a new cam :confused:

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THanks .. we will have a look at the decompressor and see if this is the issue while we are in there.

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turns out that the only problem was the cam was not lined up right @ TDC. When put @ TDC the cam was not at the correct timming. Fixed it , put it back together and it cranks up with one kick.

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