Mariner Boat 1989 not running right?

[Brandi]

My husband and i just bought this boat it sat for 3 1/2 years before we bought it never been used the whole time. But when we took it out on the water it only runs about 1500 RPM's and only goes about 10-15mph. Does anyone have any idea why. My husband has cleaned the carborators, checked the plugs, changed fuel filters, cleaned out gas tank, check reeds. What else could it be does anyone have any idea we are stumped.
It is 1989 mercury mariner motor, PLEASE HELP

 

[ezmobee]

Re: Mariner Boat 1989 not running right?

The guys will need to know the horsepower of your motor Brandi.

Based on nothin..sounds to me like you're not running on all cylinders.

 

[Brandi]

Re: Mariner Boat 1989 not running right?

It is a 115 mariner it has 4 carbs, 4 plugs and it has spark to all the plugs so.. But it is a 115 mariner. the gas tanks has been cleaned and so has the carbs and the reeds so. what else could it be?

 

[Dave1027]

Re: Mariner Boat 1989 not running right?

Why do people always go after the reeds? Fact is the reeds on the motors are super reliable. Now the ignition system is something you need to be looking at. Make sure you have spark to all 4 plugs with a timing light or spark tester. Next check timing and ignition system voltages with a DVA. After that is verified start looking at the fuel system

 

[Brandi]

Re: Mariner Boat 1989 not running right?

It runs great as far as the gas and oil and all that goes. it runs fine doesnt skip or anything doesnt quit it will just only go about 10mph... i only goes so fast it will only run about 1500 RPM's. I talked to a mechanic and he said that it could be the starter box, cause it is getting spark to all 4 plugs. But we dont know how to test the starter box. Anyone have any idea how?

 

[Dave1027]

Re: Mariner Boat 1989 not running right?

Could be high speed stator windings are bad. Check all connections to the switchbox. Take each one loose one at a time and buff them to a shine.

 

[markmc59]

Re: Mariner Boat 1989 not running right?

just a guess here, but sounds like that stupid little idle control setup, if it has it on that engine, it will shut down the rpm and give you this kind of reaction at times