ccs
ArboristSite Lurker
I was wanting to know why the compression is different depending on whcih way you rotate the crankshaft.Most 2 cycles I have checked have about 10 pounds more compression turning them backwards versus the way they were designed to run.It looks like the manufacture would design them to run the way with the most compression.I know that most 2 cycles that are used to run both ways ussually have more power in reverse.It must have something to do with the air flow in the block as to which way the crankshaft is turning.The port timing would be the same in either direction.I have check engines with reed valves and piston ported and get about 10 pounds differance with both.