"Short Wave Sportfishing" wrote in message
...
On Wed, 03 Nov 2004 22:38:05 -0800, Scott W. wrote:

On Wed, 03 Nov 2004 13:31:17 GMT, Short Wave Sportfishing
wrote:

Why do you feel the need to test compression?

Want to check out a motor before buying. I don't know what situation
it's in, a garage, basement, whatever, 'til I go to see it. Its
getting real cold up here (Ontario Canada) and I doubt its on a boat
at this time of year.

Then just crank it over - no need to get overly complicated.

However, compression tests don't tell the whole story - it would be
nice it you could start and run it for five minutes or so.

A squirt of oil and a worn engine will show good in a compression test. Run
an engine untill warm, can it idle at lower than normal rpm smoothly? look
at the exhaust what color is it (oil or water vapor in the exhaust) then
remove the distributor coil wire and test the compression. Look at the
engine oil. Also many times a salt water engine will overheat at full load
because of rust and scale in the cooling system. How do you check for that?