Whaler Central - Boston Whaler Boat Information and Photos

Posted by Derwd24 on 02/01/08 - 10:33 PM

Been looking at used engines to repower our 22' Outrage and am wondering which is more important, total engine hours or compression numbers, and would appreciate any input on where to draw the line (eg no hours over... no psi under...).

Edited by Derwd24 on 02/01/08 - 10:41 PM

Posted by PaulTarwater on 02/02/08 - 2:29 AM

DERWD24, they are both important but don't be afraid of a motor if the hours are a little high and the compression a little low. The motor will still run fine and give you several years of service and is often a good bang for the buck. Just realize that it is not going to have the punch of a new one...but it will still get you to your fishing hole albeit a few minutes late. The main thing to look for on a used engine is whether the compression is even on all cylinders. A 2 stroke engine is a simple creature with little to go wrong if proprely maintained. My '73 Johnson has around 350 hrs and 95 psi compression on all cyl and runs/idles like a dream... and its 35 years oldl!! Many want higher compression on a used motor but high compression does not guarantee the engine's longevity. Look for the even compression. That indicates the engine's overall integrity and you can run it for years even on a lower than desired compression and that is money in the bank. You just won't have quite as much oomph. Compare mine to a new 60 hp ETEC and I bet the WOT isn't more than 4-6 mph difference. Minus the waves to slow you down, the new motor might get me to the jetties 2 minutes earlier. A small price to pay since I bought mine for $250. Buying a pre-owned outboard is always is a gamble...but if you check it out properly and look for the even compression and clean carbs, I would not hesitate a bit. Even rebuilding the carbs is a heck of a lot cheaper than buyng a new one. Many WC members run older outboards and love 'em. Paul

Posted by sraab928 on 02/02/08 - 5:05 AM

Dave, for me I always check compression. I make sure that the numbers are all pretty close to each other - if one cylinder is more than 5 or 10% of the others it would indicate a problem. As for the actual numbers it would really depend on the motor you are looking at. Some motors have notoriously lower compression than others (ie the V6 omc loopers). I also factor in the overall appearance of a motor. Does it look like it was cared for etc. At the end of the day buying an older used motor is a crap shoot at best. You can get one that lasts for many years or you could get one that lasts for a few minutes.... Lets hope the latter does not happen to you.

Good luck in your search.

Posted by Derwd24 on 02/03/08 - 9:57 AM

Thanks for the replies. The engine that came with the boat was an '87 225 hp looper and the compression was about 90 per cyl, which seemed low, but like you say Scott, some of the loopers are low. Engine lasted a bit more than 3 weeks before blowing a cylinder. I understand that used engines are a risk, just figured if I had a reference set of numbers going in, that would help in my decision making. Is there an "average" number of hours per season for an outboard like there is for a car mileage? And is there a ballpark number of hours to stay away from, like anything over 500 or 750? I assume in the non-looper engines that any compression under 110 is a warning sign? Thanks.