Don't run it too rich (do not 4 stroke engine, run about 500 rpm shy of max lean rpm on break in) or you could cause damge to your engine. Here's why:

That pinch you are feeling is caused by the fact your engine is not a ringed engine, the cylinder sleeve is tapered to insure a proper seal as the engine heats up and expands. Try this to verify my statement, take a torch or heat gun and carefully heat the head of the engine 360 degrees around. Rotate engine and you will notice the ABC "pinch" has decreased a bit and the engine is easier to turn over. IF engine is run too rich, it won't heat up enough for that pinch to decrease, consequently, the pinch may cause excessive load on the engine's connecting rod and this part has been known to break in tight/new engines.


Also, if the pinch is too tight for your starter, apply heat to the engine (as mentioned above) is a perfect way to get a new/tight engine running for its first couple of starts. I do this with all of my Norvels that are very tight when new.