All these pics and info were donated by Motorrad.
Crank seals are meant to seal pressure... but they also are exposed to vacuum in a 2T motor. and thus.. they way they are designed.. will show problems under vacuum that wont show up in pressure test.. Pressure test is ONLY good for finding gaskets leaks (In my humble opinion)....
Needless to say.. I test both.
when I get done with a K5 motor.. it will hold 7psi overnight.
so..
Items I use
1 3/4 plug
2 1/4 Plug (had to shave it down some in lathe... could do by hand with a grinder too I guess)..
Old spark plug with innards busted out. and a .25 barb. soldered together.
the reason I used that barb.... is I have a VERY accurate Bicycle pump. (wife races) that reads low pressure well, so the shrader end will seal against it. as also my hand vacuum pump hose goes right on it.. so I can swap between pressure and vacuum easy.
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