[mizzymatt]

I recently rebuild the top end of my 400 it smoked real bad put a 416 on it and a stage 1 hot cam lapped the valve and i first started it looked good started right up no smoke no odd sounds then broke it on one full tank of gas didn't hit it hard didn't let it get to hot then the after that i ride for about 15 minutes and it gets hot and smokes oil out the exhaust then i let cool down and it stops till its warm again valve seals????????