1975 Mercury 1500

[catfishr1]

Howdy: Same motor differant problem. Decided to put a water seperator fuel filter before motor. I researched it & went to xxxMarine , told them exact year & model of outboard i had. They sold me a mercury 25 micron fuel water seperator kit. I carefully installed, went to lake. as passed outter buoys dropped hammer. Squirted right up on plane, at about 3800 rpms it bogged down. Could only run at 4000 rpms. Got home called Mercury Marine , they were lived. Said they should not have sold me that filter for that particular outboard. I done a compression ck. Sun. , found out #2 is now 19# lower than rest? Could that have burnt that piston that quickly? Thanks for all input. :facepalm:

 

[Chris1956]

Re: 1975 Mercury 1500

Gee, I would not have thought the filter would be an issue. The fuel pump may need to be rebuilt, the fuellines may be old or too small, or there could be a fuel tank issue. That filter ought to be rated for at least 20GPH, which is plenty for your motor.

The lower compression in in an odd cylinder. You might give it some carbon guard or Seafoam treatment and see if it gets better. You can also inspect the cylinder thru the transfer cover plate.

 

[catfishr1]

Re: 1975 Mercury 1500

Thanks for tips Chris1956. Am going to ck all you suggested. Also going to try the seafoam.