I don't look at utube but if it has a weak spark when pulling the cord slowly then I would assume the spark is good when pulling it quickly so why change the flywheel?
Mowerfreak, I had one of those motors where the compression was so low I had to put my finger on the pull start pulley to prevent it turning while I wrapped the rope on it because it wouldn't come up against compression but it still ran well and cut the grass for years

Last edited by NormK; 24/02/17 03:30 PM.