I finally found the problem and I'm ashamed to admit it was my mistake. I have a spare Ace 90 engine so I popped the clutch off of that and compared the two setups. Turns out I had the rotor gear on upside down which made it sit way too low and interfere with the primary gear. After a few dope slaps...

Ok, I filed the splines on the primary gear and was able.to install it as I believe it came off. Same problem as before. It's gotta be on the pinion side of things, I think. If the pinion gear sat a millimeter higher, there wouldn't be an issue. I thought that maybe when I installed new crank bearin...

I don't think your off your rocker at all. I'm pretty sure the primary gear went on opposite of how I have it, but I cannot get it on any other way. The gear looks symmetrical, but there may be a subtle difference between the two sides. No matter how much I try, it won't even begin to slip on the sp...

Thanks Hodakamax. Good luck with the ice storm and be safe!

Yes, it is. With the rounded side facing the engine.

I'm rebuilding a Super Rat 93 motor and have run into a problem during reassembly. The clutch rotor gear is contacting the primarary gear when I titghten the clutch nut down. Everything spins freely on its own but it seems the rotor sits just low enough that it hits the primary gear during engine ro...