What's wrong with my Hobbit? Used to do 30-35 mph all day, suddenly started topping out at 15 mph, and low-end power is gone.
Near-stock '78 PA50I -> PA50II conversion ('II' jug, intake, carb, ramp plate). Only other modifications are air filter, MLM sidebleed, 1.5k Dio springs, and drilled-out 'II' rollers, all of which it ran just fine with previously. Timing is spot-on the 'F' mark on the flywheel. Compression is ~150 psi. Jetted at 80.
I must be missing something simple, but I'm running out of ideas here.