My KDX is screwy--yet another carb problem!

[nickBeers]

I have an '82 KDX 250. The stock main jet is 162.5, but when I bought it, it was running a 125. It ran really crappy all around so I got a size 160 jet. Put it in, and the thing ran the best i have ever seen ;) , that is until I put the air filter on :( . Now, I figured this meant that my filter was clogged, so obviously I cleaned it, but to no avail. It will run low-bottom mid range so-so, but when you give it more than that it just dies right off. Normally, if you let the throttle go it will recover. Help?!? My gut instinct was that it gets too much fuel w/ the filter on so put in a lower size jet. Also, one of my reed petals is broken but I have ordered new ones already.

Thanks for the help, Nick

 

[David Trustrum]

Well the reed will need to be replaced before any tinkering or conclusions are drawn.

Most important is to be sure there aren’t any airleaks either in airbox/boot/mainifold + the Crankseals are not leaking (look for oil from seal under flywheel or use of g/box oil.

Then perhaps you can say after cleaning the carb & inspecting the jets for wear -which are probably are ovalised by now. & the float jet is sealing. Then you can say, ok maybe I should try some smaller mains.