Hey guys so I rebuilt my bf 750 this weekend and the engine is missing a little bit. It runs fine on a cold start but as it warms up the worse it gets. What does this mean/what should I do? Dont know if this helps or not but after it sat for 1 week I started it again to see if it got any better and it was hard to start but it hasn't been run in a year and the gas is that old too. Thanks