What I have done is make the gasket where the cylinder meets the case out of a gasket making goo! It is locktite brand something or another. This is what us engines recomended for this job. When you say the crank seals, do you mean where the crankshaft exits the case? I am not sure if fuel flow is the problem.

You decide: when I close the choke on the carb, I flip the engine over until it runs for about 4 pops and dies. I then open the choke and set the throttle a bit above idle. Next, I proceed to flip the engine over. It will pop-pop-pop-pop for about 3 or so flips and then will do nothing unless it is rechoked.

I have made sure the pulse hole out to the carb is open and I believe all else is tight.

Just a thought. How big should the spark be when the engine is turned over? I removed the plug and touched the engine with it while turning over the prop. The spark is tiny and blue. The spark on a US 41 I have seems to be much larger and brighter. The spark on the q-35 is tiny even when I use another mag unit and another compatible flywheel.

Thanx,
Tom