I broke in my trx engine by the manual and never had a problem but now that I know a little more, I use the heat cycle break in. Just makes sense as far as letting the metals hit a certain temp (usually 200-220) then cool down. But after your done with the heat cycle, go easy on it for the next 10 tanks, running rich. You want to give the motor plenty of time to work itself in before you start to really tune for performance and hammer on it. I broke my picco in using the heat cycle method and it still has a lot of pinch after running a gallon through it.