Rough running 20 hp Mercury

[Laddies]

Re: Rough running 20 hp Mercury

Look like fun, enjoy it Jake

 

[Motor Boater Bill]

Re: Rough running 20 hp Mercury

Glad to hear you've got it straightened out! Now make some blue smoke and catch a bunch of fish!

 

[james33]

Re: Rough running 20 hp Mercury

Hey guys...sorry to change the topic but i own the exact same motor and seem to be running into many problems....about two or three years ago my boat with the '74 mer 20 Hp on it sank. it was only submerged for a few hours and upon retrieval i was able to get the motor to start up with ease. since then i havent used the boat and the motor has developed problems....my first problem is that the impellar wont "Pee". I recently installed a new impellar and seals but came out with no luck. the motor will not circulate water. my second problem is that the motor will not advance to full throttle... I was using the motor (without water circulation for one weekend, for only about two or three minutes at a time and the next weekend when i went to try it the motor would only give me half throttle. I have checked the linkage and made sure the gas tank valve was open...Any suggestions would be greatly apreciated seeing as i would really like to use this new motor on my new hydrostream voodoo mini this summer.....

P.S this motor uses a standard Mercontrol remote system.

 

[Motor Boater Bill]

Re: Rough running 20 hp Mercury

Let's talk about the water first. You may have water circulating and the pee hole is just plugged. This is VERY common. Clear the pee hole with a wire or length of string trimmer string. If that doesn't clear it remove the rubber hose that goes to the pee hole and clear the entire hose. I have seen this hose entirely filled by mud dobber nests. Still no pee? Put your hand on the exhause cover on the side of the engine and see if it is hot or cool. If it is hot there is no water circulating. If it is cool, then you have water but the pee hole is still clogged. Don't run it without water circulating or your motor will be ruined very quickly. Your "half throttle" condition could be lack of spark on one cylinder, check this with a spark checker. But fix the water circulation first!!!

 

[Motor Boater Bill]

Re: Rough running 20 hp Mercury

By the way, it's fine to "hijack" and old thread, it saves typing in the same responses and diagnostic info, but it's probably a bad idea to hijack several threads with your same question, as you'd have to follow all of them to get your responses and those of us trying to help would have to read all of them to work together in assisting you. Hope this helps!

 

[james33]

Re: Rough running 20 hp Mercury

Thank you.. I have yet to try this because i am home for the winter and my motor is at the cottage.. Could the lack of power be because of a faulty linkage or maybe even overheating?

 

[james33]

Re: Rough running 20 hp Mercury

Thanks a lot...when i start the motor it pees only slightyl...maybe a dribble...does this mean i have to clear the hose?... And if i put my throttle lever into reverse i can rev the engine to full throttle...though i dont do it for long because of my circulation issue

 

[james33]

Re: Rough running 20 hp Mercury

P.S this motor is converted from a tiller motor

 

[james33]

Re: Rough running 20 hp Mercury

P.S this motor is converted from a standard tiller motor

 

[james33]

Re: Rough running 20 hp Mercury

Hey guys just to let u know i made my own thread called 1974 mercury 20hp troubles...
any more help would be greatly apreciated