[badkarma1109]

well I started to tear down my 91trx250x and I am finding that things are missing like the whole air filter housing. so looking at ebay my question is how far in years and how far in modle can you swap parts ( 89 250 air filter housing fit)

 

[tomgodd]

I believe all 250X parts are the same. A 300ex airbox may work aswell. Not positive.
They are the same quad asfar as frame. the motors are alittle different. Stroke and bore are different. The 300 ex also has an eletric start. But My buddy has both and they look almost identical except for the electronics to do with the starting.

 

[mud99]

I agree with Tom. I think you would be good on any year 250X