Can we discuss the practice of testing crankcase vacuum on a small OMC?

[SeaKaye12]

Hi...

I was reading an article over on Duckworks and ran across something that I'd like to learn more about. He shows a home-made crankcase vacuum "test plate". Look at the picture.

http://www.duckworksmagazine.com/07/columns/rob/index3.htm

I'd like to know when this sort of testing would be appropriate and how to evaluate the results. I know that this is a great place to learn....so here we go

Thanks, Chuck

 

[Haffiman]

Re: Can we discuss the practice of testing crankcase vacuum on a small OMC?

It may partly give the condition from piston rings and down, opposite the compression test that gives from rings and up. It should be about even. If not, probably a crankshaft seal is gone. There are however no given and historic values for this kind of testing.

 

[clanton]

Re: Can we discuss the practice of testing crankcase vacuum on a small OMC?

Search motorcycle 2 cycle racing engines for more info on this.