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rm 250 piston problem(maybe)

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i just bought a 2006 rm 250 , sold he 2006 rm-z 450 for it(getting way to many hours on it):thumbsup: .

and i have a 1997 rmx 250 and, the 06 is makin a pinging or knockin,:thumbsup: not loud but you can hear it

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from the time I start it to the time i turn it off, from slowin down going into a turn, when the engine is still revved up i notice it. and i just cant figure it out :thumbsup:

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It could just be something loose. Fire it up and listen around the engine to see if you can locate the source of the noise.

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did you buy the bike used? if so take jug and piston off and measure the piston/bore clearnce (should be around 2 thousnads of an inch new, at 6 thou you want a new piston or it will start wearing the bore), if the clearnce is excesive you could be getting pistong slap.

if the piston is in spec, while the cylinders off check the big and little end bearings, if either has any vertical slop they'll make a distinct metal on metal clapping noise (expect them to move side to side a little bit (about 1mm, so around 1:20th of an inch).

while the jugs off, also check to see if theres carbon build up, if there is a fair whack of carbon on the head and/or piston it can raise the compression enoguh to cause it to ping, just off idle under heavy load she will ping, but that's the only point i have ever gotten my RM to make funny noises.

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Before you do anything try to run something like Sunoco 104 or 110 race gas. Use a 50/50 mix with premium 92 pump gas. Mix it at 40:1 using a good quality oil such as Maxim Castro 927. Make sure your jetting is correct. Stock or not these bikes will ping under a heavy load but only under a heavy load. If it's doing this all the time then theres something going on in the top-end. If it's doing this all the time fire it up and use a hose up to your ear to pin point the location it's coming from and go from there.

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figured it out it was the exhaust, where it connects to the block there was a small about half a millimeter big, and i put jb weld on it and the pinging stopped, i dont thing that pipe was made for the bike to you the true, bolts barely line

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or the pipes been dented and bent, doen't take much.

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