So I bought a lakota 300 last year.
Redid the head so now it has good compression.
Has spark
But when I attach the carb sometimes it backfires out the carb so hard it blows it off.
Wtf is going on here.
I believe I timed It properly. I've set the valves in all types of different ways to see if it will change anything.

What steps would you take? I'd pay someone to help me fix it. Don't really want to take it to a shop.

 

Sounds to me like timming is way off

 

First check the TDC mark against reality, ie, is the piston at TDC when the timing mark says it is. Look down the plug hole and watch for the piston to get to TDC then check the timing mark. Difficult to be exact, but if it is out, due to a sheared key on the flywheel, it is usually out a lot. If it is out, you will have set the cam timing out too. Double check it anyway, There are usually two different marks on the cam sprocket, one for 300 and one for 220, are you sure you got the right one? Finally, are you certain you slid the sprocket onto the cam's keyway?