How to do leak down test ?

[Scallywag1]

I'm wating on a leak down tester. I've been reading on how to use this tester. I can only find info. on car engines. Says to go up to 100 psi. I don't think I want to put 100 psi in my motor. I've only used a compression tester in the past. Thanks

 

[ezeke]

Re: How to do leak down test ?

It is difficult to do a leak down test on a two stroke crossflow engine because of the design. You have ports on two sides of the cylinders that will leak any pressure unless the piston is balanced perfectly at or very near the top of the stroke and locked in place.

Most don't bother with the test because the compression test is adequate and reasonably reliable.

 

[Benny1963]

Re: How to do leak down test ?

i agree with ezeke i tried it on mine its a pain and most outboard mechs claim not reliable. a cranking compression test is the way look for numbers that are equal between cyls a low cyl will tell ya if ya have prob

 

[R.Johnson]

Re: How to do leak down test ?

I made a piston stop tool to lock the opposing piston. There is certainly nothing wrong with applying a #100 to the cylinder. What do you think that burning fuel does? It is a compression tester that can throw you a curve. I use both test's, but I find the leak down much more reliable. Don't try a leak down by having someone hold the flywheel with a wrench, that would be an excellent way to get hurt