I have a yamaha ovation 340 with a single 34mm mikuni carb, oil injection has been removed. The sled wants to foul the pto plug,it seems to be the worst at full throttle. The mag plug is always nice and dry. I have tried switching plug wires around with no change. 100psi in both cylinders. Bad crank seal would should cause that cylinder to run lean not? Fuel pump pulse line didn't have any gas in it. I don't know what else it could be.