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Rebuilding an old Mercury

Posted: May 30th, 2008, 11:18 am
by Olebiker
I need some advice from folks who know more about outboards than I do, which is nearly everyone.

I have a 1984 50 hp Mercury that runs well but just has very little power. It will only push my Bass Tracker about 24 mph.

I would like to buy a new motor, but I don't see that happening any time soon. Would it be a good idea to have such an old motor rebuilt? Has anyone had good results with any local dealers doing the work?

Re: Rebuilding an old Mercury

Posted: May 30th, 2008, 11:38 am
by wevans
Check the cylinder presures, what is the rpm's at WOT, there are many things to check out before a rebuild is decided on :-D BUT, it would cost much more than the motor is worth if a rebuild is called for :smt012 :beer:

Re: Rebuilding an old Mercury

Posted: May 30th, 2008, 11:44 am
by Olebiker
The boat has no gauges, so I have no idea how many rpms it's turning.

Re: Rebuilding an old Mercury

Posted: May 30th, 2008, 12:32 pm
by wevans
http://www.thetoolwarehouse.net/shop/ESI-325.html" onclick="window.open(this.href);return false;

You should be able to find something simular locally :-D without knowing your WOT rpms, there is no way of knowing if you have the correct prop on the motor :smt012 any local mechanic can do the compresion test on the cylinders "does not have to be a marine mech." :beer:

Re: Rebuilding an old Mercury

Posted: May 30th, 2008, 2:48 pm
by MrGreenJeans
Dick,

I have a compression guage if you want to hook up some time I will be happy to test you motor compression for you. That motor is 2 cylinders right? If you do need to have work done, I have used Websters marine in Havana and he seems to be reasonable.

Re: Rebuilding an old Mercury

Posted: May 30th, 2008, 4:06 pm
by FUTCHCAIRO
I BELIEVE THAT A 50 H.P. MERCURY WILL BE A 4 - CYL. INLINE ENGINE, IF SO IT IS A GOOD ONE. CHECK THE COMPRESSION AND IF THE CYL. IS 120 # OR BETTER AND ALL OF THE CYL. PRESSURE IS WITHIN 5# OF BEING THE SAME IT WILL BE IN PRETTY GOOD CONDITION. YOU MIGHT CHANGE THE TILT LOCK PIN AND RAISE THE ENGINE A NOTCH AT A TIME AND TRY IT. IF THE ENGINE IS TOO FAR TOWARD THE BOAT IT WILL MAKE THE BOAT PLOW THROUGH THE WATER AND BE HARD TO STEER. YOUR ENGINE SHOULD BE BACK FROM THE TRANSOM ABOUT 5 DEGREES FOR BEST PERFORMANCE. AT LEAST THIS IS WHAT I HAVE SEEN IN CHECKING OUT AN ENGINE THAT I HAVE NOT KNOWN.
PA THE OLD MAN OF THE SEA

Re: Rebuilding an old Mercury

Posted: May 30th, 2008, 10:51 pm
by grim reeler
My 50 merc is a 3 cylinder. It could be any number of things from as simple as a fuel filter or fuel quality to carb issues or compression problems. If it ran fine before and has slipped since, then I would not think prop or trim was the problem. Pitch and trim can be adjusted if the motor has just gotten old and a little tired, but I would look into other possibilities first. Testing the compression is a good place to start, and I can also vouch for websters marine as a good place to take a motor for a reasonable price.

Re: Rebuilding an old Mercury

Posted: May 31st, 2008, 3:20 pm
by Olebiker
I sure appreciate everyone's input. The War Department has approved the purchase of a new outboard, but I have to put up with the old one for the rest of this year. I think she got scared this morning when she saw me sitting on a friend's Harley. She figured she would rather have me bass fishing than riding a motorcycle.

Re: Rebuilding an old Mercury

Posted: May 31st, 2008, 4:15 pm
by wevans
I gotta remember that one for later use :-D :thumbup: :thumbup: :beer: