Originally Posted by G600
Thanks, this is VERY interesting.
How do the two engines compare? Do you feel that the 600 (when it lived) had more power? What about throttle response??
I can not give the 550 a fair appraisal because the motor as purchased had a few thousand dollars in performance upgrades for racing. It looks dirty and it's a sleeper motor.
I do know the 550 is a lighter plant. I had to lift both engines by hand for the swap, and while I wish I had taken a moment to get them on a scale, I did notice what felt like a substantial weight difference. 15-20 lb. A big part of this weight difference is in the starter motor, starter clutch, heavier flywheel (to connect to starter), starter idler gear.
So the 3-4 horsepower difference between the two motors might be a wash when you factor in the weight difference!