leakdown tester on 2 stroke

[itstippy]

Do you experienced wrenches use a leakdown tester as a diagnostic tool to evaluate 2 stroke outboards? Advice? Techniques? Tricks? Tips? Idiot idea? Surely this has been covered before, but I tried searching old posts and I'm not finding what I want. Humor me please! Just trying to add to my bag of tricks. Thanks.

 

[WillyBWright]

Re: leakdown tester on 2 stroke

You can, but the rings are designed differently than 4-stroke rings. I don't know what percentiles would mean what. I'd expect more leakdown in a 2-stoke to still be acceptable.

 

[itstippy]

Re: leakdown tester on 2 stroke

Thanks WillyB!
The leakdown tester is rattling around in my bag o' tricks right next to the compression tester. It makes me wonder. I suppose leakdown testing procedures, if possible at all, might vary according to the type of 2 stroke. I work primarily with older single carbed 1 and 2 cylinder models, OMC watercooled and oddball "aircooled" stuff from the 1940's - mid 1970's. Any way to use a leakdown to test crankcase integrety (reeds, upper & lower seals, exhaust port sealing)? A compression test does an adequate job on the rings & cylinder wall seal, or has so far, for the low tech stuff I work on. Of course, any advice for leak testing any 2 stroke (or 4 stroke, for that matter) is most welcome. Some reader will (or won't) learn something useful. Who knows, maybe some day I'll work on an outboard that's less than 30 years old myself.

 

[JUSTINTIME]

Re: leakdown tester on 2 stroke

the best tester is a leak down on the block

but u will need to block off the exhaust and intake passageways

what this does is to check if all gaskets and seals are in good condition

but to do this,u have to pull the power head

 

[Laddies]

Re: leakdown tester on 2 stroke

HUH:/

 

[JUSTINTIME]

Re: leakdown tester on 2 stroke

HUH:/

tell me how do u check crank seals then?

 

[Laddies]

Re: leakdown tester on 2 stroke

The top seal you look at if is leaking there will be oil under the flywheel, the bottom has to seals both installed lips down and if they are leaking the engine drops the bottom cyls when in the water but runs alright on a flushing hose