GY6 180cc By 180ccratruck (Read 443 times)

[180ccratruck]

It just won't turn over. Got spark,got fuel and exhaust(can hear it and smell gas). Used to be a 150cc. Upgraded fuel pump, oil pump, 11 pole stator and a larger battery.
Suck, bang, blow. No bang help please and thank you.

[geh3333]

Possibly could have a vacuum leak that's sucking in too much air

[geh3333]

Is it turning over ok? If it's weak you may have a hard time starting.

[grrbrts]

How do you know if it is getting good spark, if it won't turn over?

[classacted]

you mean IT WON'T FIRE.  you are stating that the starter is moving the piston and you're not hearing that 'pop' when the engine takes over by itself.  correct me if I'm wrong.  that's called a 'crank, but no start'.

if you have a compression tester test for compression.  120 lbs is marginal IMO.

if you have well over that, I would suggest disconnecting the air filter and exhaust so it can breathe, then pulling the spark plug out and wiping it off so it's dry.  crank the cylinder to shoot gas out because it could be flooded.  if it's totally dry, find a way to squirt a little gas directly in the spark plug hole. 

did you loosen the screw on the float bowl to see if there is gas in it?  how old is the gas?

[grrbrts]

Did you upgrade the flywheel?

[geh3333]

I had to get a high torque starter when I did my 63mm build . The stock starter had a heck of a time trying to turn the motor over. Even with the taida high torque starter, it still sometimes gets "caught up" on the compression stroke and I have to hit the start button again , but it def starts much easier with the new starter. I've had issues before with a weak battery keeping the scoot from starting . It would turn over , but it would turn over very slow and it would cause the scoot not to fire.

[classacted]

I hope the original poster solved his problem.  I don't think he/she is going to reply.

[geh3333]

Doesn't look like it

[brutus413]

Not sure if it helps, but my 63mm bbk went 750mi before the crank went bad. That was 15 months ago and I just haven't had the time to get into it. Finally took it to a mechanic and they want to replace the entire engine. I second the high torque starter option, but I never had an issue with the stock starter until the crank started binding up.