I put my engine back together today and leak tested it with the following results;
The left/upper cylinder holds 8psi for at least 10 minutes with no noticeable drop in pressure shown on the gauge.
The right/lower cylinder however, shows an immediate drop as soon as pressure is put in. It settles at about 2psi but after 15 minutes reads virtually zero on the gauge.
I kept topping the pressure up and spraying my special Rocol leak detector spray around possible leak points. If there's even the slightest gas leak, this stuff will find it. No external leaks were found though.
I next plugged both inlets and pressurized the right/lower cylinder again to see if cross leakage would eventually fill the other cylinder and hold pressure once the whole engine was on 8psi.
It did indeed. After topping up a few times the other side of the engine eventually filled to 8psi after which the gauge held pressure for 15 minutes with no significant drop.
So air seems to be able to pass from the right hand side of the engine to the left through the center crank seal. BUT it cannot pass from left to right which i don't understand at all.
I found a comment in an old post from a member called jeffco which read;
"Whenever I do a primary leak check on a twostroke, I do a vacuum check as well as pressure. I have had crank seals that would seal positively (100%) on the pressure check, but would leak terribly when a vacuum was applied. (-5lbs) Just something to keep in mind."
This sounds like the same sort of thing.
Does anyone know what's involved in fixing the problem?
Is it a guaranteed seizure if i were to ignore it?
Thanks for any help gentlemen.
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