Popping while idling

[matt-itude]

when you turn the engine over slow like by hand. if the power valve or attached components are moving then i would say it is hitting. if youve had it running i would think it would have left scars on the side of the piston too. once again too much yz specific on the power valve linkage (no mental picture in my little head) we need someone to sound off that really knows the yamaha system.

 

[jakeyz250]

I have the pipe off, and I can see the piston, and there doesn't appear to be any excessive wear on the piston, I think that it either had jsut started hitting, or something I did while checking things out finished the job.

If anybody wants pics, i could probley take some and email them..

 

[kdxman15]

is the popping comeing from the pipe. u say it runs well so whats the problem. r u running a shorty silencer. i herd a 95 cr250 the other day, had the same pipe as yours. it made the loudest popping nosie at idle but the bike flat out ripped.

 

[jakeyz250]

I don't have a shorty silencer. I have the stock one. I really coudn't tell you where the popping is coming from. Its been awhile since I had it together, but I think its from within the motor. It may just be the pipe though.. Do you know what kind of mods the cr250 had, as far as engine. Mabey bigbore or something?

 

[jakeyz250]

After I put everything back together, i started it, and now the popping is about 25% less loud than it was before, I don't know if it was something I did on purpose or what.

 

[a454elk]

Sounds like the pipe may not be seated in the head, check to see if the metal flat gasket ring is in between the pipe and the head. Maybe it's sucking cold air in on decel through the pipe and the head???

 

[jakeyz250]

The pipe doens't go completely on, its alittle crooked in there, like the top is most of the way in, but the bottom is pulled out alittle.

 

[matt-itude]

mabey were all trying too hard. you know what they say fix the obviouse first or youll end up fixing it later with a headache.