won't start in forward only in reverse

[medman22]

Sorry, probably a dumbass but why would a crank seal let it run in reverse and not in forward, but after running in reverse it works in forward ?

[JPonLKN]

I guess the first thing to determine...what cart are we talking about? old 2-stroke where the engine runs both forward and reverse, or a 4-stroke that has a gear change in the transaxle? Stock belt and clutches? Big block or stock motor?

[CP241]

It may be due to the spring in the seal “seating” better in reverse but honestly I’m not really sure. I have seen it many times that crank seals will make it run in reverse but forward suffers.

As said, also a good chance the ignition timing is off.

You gotta pull the flywheel to check the timing anyway, and the crank seal is right there. May as well replace it while you’re in there. The clutch side crank seal is must easier to get to but rarely fails (of course).


Per jponklin good point. This is also assuming it’s a 2 stroke marathon. If it’s a newer cart then that changes the game completely but I’m assuming it’s an older one.