RM250 Knocking

[xMajasteex]

Hey New to the forum , relatively new to dirtbikes period... I just had the top end replaced in my 2000 Rm 250. The factory piston came out same size went back in. When i got the bike back i flushed the gas and put fresh gas in cleaned the filter and got a new plug and now the bike is knocking at idle. Does anyone have an answer to why or better yet what I have to do to fix this issue. Response would be greeeeatly appreciated.

 

[Agitator]

What Octane level of gas are you using?

Low octane levels in your fuel are usually associated with preignition, knocking, etc... (except with a 4t, where there could be valve problems)
I think most people use at least 93 (best gas-station grade in most areas)

If you didn't use high octane gas, you might want to try that- It might be a simple fix.

 

[+30]

I had the same problem here, Ive put many a piston in but this is my first one in the zook. noticable knocking that went away after warm up. I was using pump gas, but the bike never knocked before the new piston, then quieted down after some gentle break-in time, bike runs and sounds fine now.