Motor will not run under load

[jimpnl]

I traded for a 7.5hp Mercury 2 stroke '73 I think. Motor start's, idles, goes into forward and reverse with ease, so we made the trade. Get it out on the water......... again, starts up nice, I let it warm up a bit, take off and as soon as I try to open it up a little it dies. So start it up again with ease sit for a few longer take off and it does it again, idle back to dock let it run for a while now it acts as if it does not want to rev to its maximum and it just will not run when under power. I have no idea what to do other than change plugs. PLEASE HELP! ...............................Jim

 

[bowman316]

Re: Motor will not run under load

maybe the boat is too big. Maybe it can just not get the boat on plane. Try adjusting the position of the motor in the water. raising or lowering the motor, tilting it.
A lower pitch prop.
if that does nto work, then you have engine trouble.

 

[jimpnl]

Re: Motor will not run under load

Thanks for the post, but it is not because of positioning of motot. It is a motor problem it just does not want to run under power it stalls then dies. Runs fine when idling in neutral untill you put it in gear and start to go it just does not want to run then dies.

 

[Willyclay]

Re: Motor will not run under load

Try engaging the choke/primer when you throttle up. If it seems to run correctly, you probably have a clogged main/high-speed jet in the carburetor. If it still bogs, turn off the choke/primer and pump the fuel hose primer bulb until it firms up. If that increases the RPM's significantly, you probably have a bad fuel pump. Let us know what you find out. Good luck!

 

[jimpnl]

Re: Motor will not run under load

Thanks. That is what I thought, just was not sure. I did pull the choke when it was runing ever so slightly and it seemed to rev up easier and run a little better. Found a reasonable mechanic in the area and am taking it ot him tommorow he said the same thing you did. Will post as soon as I know whether the carb rebuild works.

 

[sschefer]

Re: Motor will not run under load

Thanks. That is what I thought, just was not sure. I did pull the choke when it was runing ever so slightly and it seemed to rev up easier and run a little better. Found a reasonable mechanic in the area and am taking it ot him tommorow he said the same thing you did. Will post as soon as I know whether the carb rebuild works.

Probably just a fuel filter.