Hard Starting Hot

[RustyPile]

Originally Posted by Carl Spangler

Was the engine completely warmed up for the 'stumbly take off' test?

Here's another easy test:
Crack the thottle about half open and see how much side-play is in the throttle shaft. i.e. clearance between the shaft and casting. A proper rebuild would include drilling out the housing and pressing in a brass insert. If rebuilt properly there should be an 'interference fit' between the shaft and brass bushings. If not done properly this could be a source of air leak and whistle.

With all the QC issues, I don't doubt that's a possibility one bit... A stiff return spring is the number one cause of throttle shaft wear..