Stihl 0 series

[Tml061583]

I have a few o series saws I want to pressure and vacuum test. Curious as to proper procedures for this. Have an 026, an 028, and an 038 magnum. I planned on blocking of the exhaust and the carburetor on the airfilter side then hooking my vacuum and pressure tool the the impulse nipple on the crankcase. My question is do I have to plug the disconnected impulse hose? Is it possible for air or vacuum to leak through the carburetor where the impulse line connects to it?

 

[J D]

You should be blocking the intake between the carb & the manifold. If you block it on the air filter side the carb will leak air arround the throttle plate shaft

 

[Tml061583]

Throttle shaft never entered my thinking. Thanks.

 

[singinwoodwackr]

If you can braise or weld you can make a test plug…from an old spark plug that you hook your Mitivac to. Close up the exhaust port and intake…remove carb and test it separately.
I make plates from scrap 3/16” flat stock and some flat rubber sheet material I got from a landscaper…drilling properly spaced holes for the various intakes and exhausts I’ve worked on.