"Scott W." wrote in message
news
Is it safe to crank over an outboard to test compression without
putting the lower unit in water, or will you damage the impeller?

Cranking it, yes, you are safe, just don't start.
On a pull-start, should be at least 3 full hard
pulls, on electric start, a few seconds. Like the
other poster posted, if you got ear muffs, put
em on if you are concerned. If its a running
motor, then just test compression after you
take it out of the water so there is still some
wetness in the column. But you'll be ok. More
interestingly is the question of what yer doing,
and why your are doing this? - what motor,
and why are you doing compression test - you
suspecting something, or just spot checking, or
buying a second hand motor or someting ? If
under 150 Psi, I might be concerned, and if
*any* difference at all between cylinders on
a multi-cylinder maching I'd be very concerned.





Scott W.