Mercury 50 hp quick fix? Seeking advice

I recently picked up a 17.5 ft fiberglass grew with a Mercury 50 hp 4 cyl. 4 stroke (like new) and have found a couple snags. The boat has sat and been worked on more times than it has been in water. Seriously, the boat has sat in the same spot for about6 years. The engine has about 15 hrs on it after a new rebuild.

Here are the issues:

Engine idels perfectly but after put in gear it sputters until a little after half throttle. Full throttle it runs great but when decreasing throttle the engine quits. That is problem 1.

Problem two (may be related) after running the boat hot for a while and shutting it down it, immediately after trying to start it again it blows the main 20 amp fuse (as manual suggested).

After the engine cools down it starts and runs fine. (besides problem 1 listed above)

Made some brief adjustments to the throttle tension it worked like a top....until first decelleration..the problem 1 continued.

The boat has lots of oil and has been very well maintained.

Any suggestions would be greatly appreciated,

:redface:

Thanks.

Re: Mercury 50 hp quick fix? Seeking advice

If the carbs have not been touched, tweeked, tinkered with then yu can remove the bottom pulgs on the carbs and fill them with mercury power tune. let them set several hours and flush new feul thru them washing out the powertune. this will most likely remove any varnish left from setting for 6 years. however, if the carbs have been tinkered with you'll need to take it to a technician to set them up properly.

Re: Mercury 50 hp quick fix? Seeking advice

Nope, nobody has touched it since the tech rebuilt it. I will try that and see how it works. I take it the fuse issue is unrelated?

Thanks for your suggestion,

Re: Mercury 50 hp quick fix? Seeking advice

this sounds like a motor tha has been sunk before . i know thats not what you want to hear - it still may be fixable though.

Re: Mercury 50 hp quick fix? Seeking advice

Curious as to what might lead you down that road. My grandfather had it for the last 8 years and I know he didn't sink it? Anything I should check?

Suggestions?

Thanks though,

Re: Mercury 50 hp quick fix? Seeking advice

generally a motor with a multitude of issues and re-ocurring issues has come into my shop as a sunk motor thats why i suggested it might be . a couple of months ago a family came in with a 2 year old motor that they were constantly going into another shop for electrical repairs - the guy kept cleaning all the connections but it wouldn't last long until the salt reared it's ugly head again . i stripped a few wires bare from the harness and showed them how the salt from a sunk motor will keep creeping up the wire , puuled the coils off and enough salt fell out to melt my driveway in the winter - then i chipped the paint off in random locations to find zinc primer ( spray can) hiding all the rust . something the previous owner didn't tell them when they bought it - but if you know for sure then disregard my comment .