150cc gy6 won't start
 

hi all I'm new here read a lot of good stuff on this forum, I used a manual off this site to do an engine rebuild(heat seized piston rings) so I rebuilt my engine did the timing started it up ran for 5 seconds then died, after that it just wouldn't start so I put another carb on tried starting it up nothing, checked the engine seems I'm leaking air past my rings.I can hear a squealing sound at compression stroke, rings are still good so yea I'm stumped .what's the cause of this and how can I fix it.also could this slight air leak cause my scooter not to start.thanks in advance.

Hi
For an engine to operate properly you need 3 things fuel, spark and compression
I would check your engines compression first
100-125 psi is good, 125-150 psi is very good, and 150+ psi is great. If you don't have this level of compression then you have bad valves and/or bad piston rings.
Take care and ride safely
Yours Hank

ok well I have fuel and spark but compression is worrying me, it has compression but I don't think it's enough my valves are good just used grinding paste to seat them right.I'm almost 100 percent sure it's the rings but I don't know why they're leaking air they're brand new, could I have installed them incorrectly,maybe someone knows the right way to install the rings.

Hi
This tutorial should help
http://www.scooterhelp.com/tips/engi....lf.vespa.html
Take care and ride safely
Yours Hank