yeah, thats 40 chain to the rear wheel. i dont like 35 going to the rear cause i have too much trouble with it comeing off all the time. the front is 35 cause i alwready had the engine sprocket. i have 13 of those engines and im going to change from one to the other, and the only srocket you can get to fit the tapered crankshaft is 35 size.--phil