Can anyone tell me how to do a leak down test?

I have a 1987 CR430 that may be needing new seals. I have a nice Snap-on leakdown tester that I got cheap on ebay, but I don't know how to properly use it. Also, it seems that I could easily blow out good seals by using too much pressure!

Any experienced mechanics out there able to run me through this process?

On a 2 stroke its not a blow by test.
Its a vacuum test, plug exhaust and intake and see if it hold 6 or so inches of vacuum.
When it wont maintain some neg pressure, the crank seals are needed

pour paraffin into the inlet manifold. if it leaks u need new seals.

I've always used pressure as a leak down test. Rule of thumb I was taught years ago is:
pump it up to 6 psi, should not drop more than 1 psi in six minutes.

I use an expansion plug in the exhaust, then made a plug with a gauge port and a schrader valve, in the intake manifold.

Hey, um Ron. The other day after you clocked out from work. The boiler in the basement of the building, stopped working. Boiler guy said the pressure gauge, some pipe and the blow off plug were missing? Ha, nice set up!

I know nothing!!

Sgt Schultz strikes again