Hello Fliped61 and Norm
The Model 73 was the last of the colts - with Model 7313 (5hp), 7344 (8hp)
and the 7347 (8hp elec start?)
My best guess is that in converting the machine to an over-powered 11hp,
the primary pulley (on the 11hp engine) is too large.
If the travel speed is too high and the transmission sprockets look original,
the first check would be with the engine drive pulley, not the chain trans
after the gearbox output.
Hope this helps
--------------------------------
Jack
