vacuum test g1

[tyivie]

i have g1 that runs great for 20 minutes then dies if i choke off the air it will run kind::::: im pretty confident in the cleaning of the carb. im woundering on vacuum testing the crank case for bad crank seals if i close the exhaust port at the carb port and put vacuum pump to impolse line it should hold vacuum right. any thoughts would help. and if you know how much vacuum it should hold. thanks

[GMB74]

You can block off the exhaust port and carb intake ports using red neoprene gasket material that plumber's use (available at any hardware store). Then apply pressure to the fuel pump pulse line. 7 PSI MAX. You can also pull a vacuum down to -7 PSI. Leakage down to 4PSI (or -4 PSI vacuum) is considered acceptable when testing chainsaws, weedwhackers, etc. I don't know what is acceptable on these larger engines, but from personal experience if you have seal problems, you will not be able to pump up any pressure or draw any vacuum on them. They will leak faster than you can pump.

[tyivie]

that is probably the problem then , guess i cant get any vacuum. thank for the reply

[skarp]

Sounds like time for crank case seals!!

Stephen