Indian stated HP Limits vs Actual....
One thing occurred to me is that the key stress components on the Indian engines may be a limiting factor.
They seem to have soft crankshafts. I wonder if the con rods and wrist pins are of true Lister quality and strength?
Perhaps the max HP rating of Indian machines is more related to metallurgy? Even if they are not bowing black smoke, they may still be close to disintegration
LOL
Just a thought.
Veggie
PS: Don't forget to factor in altitude. I live at 3300 ft elevation and engines must be de-rated by 10% here.