I bought a US41 that had very bad vibration at full throttle. I sent the engine back and when I called it was looking at a long time to get the crank, flywheel and prop hub to fix it. A "new" engine showed up at my door. I'm very pissed at them for doing this because my aluminum muffler and linkages didn't make it back with the "new" engine and the "new" engine is definitely NOT new. Anyway, I'm a push over and I tore the engine down and I have .003" runout on the prop hub and 0.000" runout on the crank so I'm happy with that, I made new linkages and a person I talked to at Hobby Services says a replacement muffler is on it's way from them.


I also found the throttle linkage was hitting the carb not alowwing the butterfly to open fully, I also fixed that. I balanced the flywheel and put it all back together. Prop hub runnout is now 0.006 but I can live with that.

Bottom line is the first ones of these I bought years ago I like, these later ones need to be discontinued or something.

And I want my muffler back.

FYI this goes on a 16' span oldtimer Quaker and it is expected at Joe Nall, Kirby and Pat big fans of the old Quakers....