stevejohns

What should the comp be? I tested mine with a decent tester engine was cold and not run for about 2 weeks. Alt was 2000 feet. lbs ran from 128 to 136. How does that sound?
thanks sj

Griff

Compression test should be done with the engine warmed up---oil at operating temperature to get a real accurate reading. The numbers would probably go up some if the engine was warm. The numbers are not BAD just slightly low. I think Merc says they should be at around 140-145 with a 10 lb variance maximum between cylinders.

stevejohns

OK thanks. I was changing the manifolds and couldnt fire it up to get to a warm and oiled state. Looks like im ok.
I did some quick and crude math , my boat has 160 hours on it. Compared to highway speeds and rpm it has about 18,000 miles on it. Not bad for 10 years old

Kokopelli

With 50 hrs on mine it tested at 165 -170 after warmed up.

MACDAD260

After 20 hours mine tested 155-160 cold.

mopower

Stevejohns, You must have been running the hell out of that poor boat since I heard SK. has a boating season about three weeks long
Math...160 hrs divided by 10 years= 16hrs a year. With a three week boating season you must really be busyLOL.

stevejohns

3 weeks????????? maybe if we scrape the snow off during week 1 and 3 !!!!!