I don't have any experience with Tiger but from the manual is says 7300 to 7800 RPM. A "break in" prop 18 X8 is recommended and then up to a 20 X 8 is OK. I know with spark you can expect an increase in power just because you can control the ignition point MUCH better than a glow plug. I would expect the engine to go into an "older" air frame so maybe the power thing might not be as big a deal??? From what I understand these engines are know for their torque. Like I say no first hand experience.

Ken

PS. I was going to have it auctioned off this weekend but when I saw a ST 4500 sell for $40 or $45, I decided I WAS NOT going to give it away.