knocking

[wildman8jj6]

hi, my rm 250 has a loud knocking when im riding it, but its fine when i sit there and rev it up. after i ride it after the knocking it idles up and down, it seems to knock when its hot bc when first pull it out and get on it and let it run for a few then go, its fine but after 1 min it heats up it knocks really bad, maybe the rings, wrist pin bearing?

 

[_JOE_]

Are you running standard compression and at least premium pump fuel?

 

[wildman8jj6]

no, its bored out to a 285 and im using pump.

 

[whenfoxforks-ruled]

Check your plug, STAT!

 

[wildman8jj6]

ya thats fine, its not the piston hitting the top, i have no clue, only thing that i thnk is the rings or ht ewrist pin bearing but they all seemed fine.

 

[_JOE_]

Was the power valve relieved enough to clear the piston?

 

[wildman8jj6]

ya thats all fine to.

 

[whenfoxforks-ruled]

Piston to cylinder clearance excessive. The pulse and sound wave are out of synchronization in your pipe. So what does the plug look like? How many turns do you have on the power valve tensioner?

 

[wildman8jj6]

the plug is burning white on the bottom. im not sure what you mean by how tight the tension of the power valve is. like the bolt underneith the cover that holds it together?

 

[whenfoxforks-ruled]

On the left side of the cylinder. There is a large cap at the end of the powervalve. There is a spring under it that puts tension on the powervalve. What do you mean white, like lean?

 

[wildman8jj6]

there are too covers on the left side and i took the one of that you can see the power valve and there was no spring. the power valve moves easily and should it be all the way down or up? the plug had white burnt on the bottom of it

 

[_JOE_]

There should be a small cover at the top front of the left side if that makes sense. At least thats how my 02 was. There were 2 small bolts that held the small cover on. Under the cover is a tensioner spring.

 

[whenfoxforks-ruled]

Number 14,

 

[_JOE_]

Thanks wwfr, looks like loosen 18 and turn 10. Same setup as my old one.

 

[whenfoxforks-ruled]

Now about that lean condition. Use a clean or new plug, run it on each circuit and find which is dry and wet. Jet accordingly.

 

[wildman8jj6]

thanks, i tighten the cap you were talking about and it seems alot better. im waiting for new head gaskets to come in then ill ride it and see if it makes the noise.