I'm trying to brainstorm this until I get to the boat again. I don't claim to be a 2-stroke expert but I've had a few and I've run them from the earmuffs, believe me, this is too much oil in the exhaust. Yes, it has the oil injection system. I did check the oil in the tank, I can't vouch for the quality of the oil but it does look clean and there's no sludge or crap in the tank. Obviously I've been all over the map on this but I keep coming back to the oil in the exhaust. I once thought it wasn't burning all the oil in the cylinder/cylinders because it was running poorly. Now I'm almost convinced that too much oil in the cylinder/cylinders is causing it to run poorly. I'm sure there's a way to check/adjust the gas/oil ratio (50:1 desired) but as of yet I don't know how to do that. I have seen several posts about swapping out the injection system for pre mix on this motor so it must be a problem. I do appreciate all the input, guys.