Hey 5HP
Just keep the flywheel. Trust me it has plenty of power to spin it. And the heavy flywheel helps keep all that torque. I never mess with the flywheels. I just leave them stock. I have a H50 Motorsports engine from tecumseh, and it came with a stock flywheel. A mikuni would work well on it. Another member Mike Harrington put one on his HM80 and loved it.
Josh