Dyno, sorry to correct you but the only difference in the 85-86 atc and 86 trx engine is a little port work. Every single part of these two engines are interchangable. Take one out bolt one in, exactly the same.

 

trx250Rob, I was just reading the info that was in an older dirtwheels mag that I have from back in 86 when they compared the tri z, quad racer, tecate, trx and atc 250r's. In there it said the atc had a higher compression motor, and thats why I said that. I'm sure you are right since you've had them apart, I was just replying from what I had read.

 

teactes are faster in the atv atc world(both modded or stock) i have raced mine and many other R 's with my tecate and it beats them and ive seen the atcs race and a stock tecate beat a piped 250r iam not downing honda i love them but id rather have the green 2-strokers

 

The atc dose have a higher compression gasket, a slight difference in porting, and some washer internals. All parts are interchangeable, though you can do everything to the trike as you can the quad. With that 50lbs or so difference it will out drag the quad. In technical riding depending on rider skill/comfort, the quad will almost always win. Remember before I start a fight I did say driver skill!

Also on ski-doo trails a quad cannon compete, the front end easly gets caught in the powder.

 

just to throw it in............. I DO have a set of showa atc250r shocks..........blue...... front and back for sale