Pressure testing

[wgr]

I am working on a Homelite 240,it has all the symptons of a air leak, but crankcase holds air pressure,should i also vacuum test ,is it common for a engine to hold pressure but leak with a vacuum test.Thankyou

 

[viking]

seal the intake and exhaust ports and apply vacume. the system should hold the vacume. make sure your seal plates are flat. I put a tube in the exhaust plate and use a mity-vac hand unit. again make sure that your test set-up doesn't have any leaks or you will be chasing your tail.

good luck

 

[Walt Galer]

Howdy,

Don't forget that the airleak could be between the carburetor and the engine. In such case, it will not be there when you pressure/vaccum test. Yes, you need to test BOTH ways. Often a seal will leak only one way!

Regards,
Walt Galer

 

[wgr]

Thankyou very much gentlemen.