Mercury V-150 Black Max powerloss

[vesper]

I have a 1989 V-150 that will not run over 2000 rpm. In neutral the engine seems to run fine, and goes over 2000 rpm. In gear the engine feels bogged down and some of the time will stall. This happened after running smoothly for 1 hour we had stopped to fish for a while. Went to crank the engine up and that is when the problem occured. I changed the inline fuel filter...nothing happened. Please help me...

 

[WillyBWright]

Re: Mercury V-150 Black Max powerloss

Pull the sparkplugs. They should all look about the same. If any are significantly different than the others, then you got problems. Then check to see if you still have spark on all of them. If you do, I'd suspect bad high speed windings in the stator which produces the power for the spark. Then it'd idle and run okay until you got to half throttle, then fall on it's face. If you have no spark on one or more cylinders but have spark on some, then I'd suspect a bad switchbox. Could be triggers or coils, but stators and switchboxes fail more often by far. Test compressioon as well.

 

[Elmer Fudge]

Re: Mercury V-150 Black Max powerloss

Try rebuilding the fuel pump and tighten up all fuel lines,if that does'nt fix it, do a compression test on each cylinder and post the results.<br />also check your carbs,could be some trash got in there somehow,even though you have filters,stuff sometimes happen.

 

[vesper]

Re: Mercury V-150 Black Max powerloss

Thank you. I will post the outcome of my trials and error.

 

[vesper]

Re: Mercury V-150 Black Max powerloss

It turns out that the left side powerpack was bad. We replaced it and the engine runs fine. You guys hit the nail on the head....thanks again.