I bought an 87 trx250x, and have removed the air lid,and opened up the exhaust a little... Im now trying to get the jetting right...
Im wondering if anyone can tell me what jets came stock in the quad.
It idles great and the part throttle is great,however I think its a little lean on top still... The main jet that was in it was a 110,I went all the way up to a 128,but still feels like its leaning out,and Im still getting popping on decel.
I would have a better idea of where to go from here,if I knew what the stock main jet was.

 

#125 normal and #120 high altitude

 

Thanks....So,I guess it is prolly still lean on the main,with no air box lid and exhaust..

I wonder why the hell,it had the 110main in it!!!!

 

my 87 250x had a 145 main in it and a cam. I went back to stock on each and it runs great. Much better.

 

Did you end up using a 125 main?

 

yes.