88 mercury black max xr4 150

[Jamskeeter225]

I have a 88 mercury black max xr4 150 runs great idling but only runs 4000 Rpms at wot it has good compression and good spark just can't figure out if the timing is off or something

 

[racerone]

Re: 88 mercury black max xr4 150

Is this something that started suddenly ?-----Could be a reed valve problem.----Blockage in a carburetor.---Flooding carburetor.----Fuel pump problem.---Sort this out before running it anymore.

 

[Jamskeeter225]

Re: 88 mercury black max xr4 150

Idk If this has anything to do with it but the primer bulb doesn't stay tight and when you trim it up all the gas runs out and notice gas in the test tank

 

[Jamskeeter225]

Re: 88 mercury black max xr4 150

Someone told me I wasn't propped right it's got a 24p laser 2 on it they said run a 22 or 23 pitch prop will that bring my Rpms up and get me speed or make me lose speed

 

[Chris1956]

Re: 88 mercury black max xr4 150

A 24P prop is a lot of pitch. What kind of boat? Are you trimming the motor?

Unburnt fuel in the test tank could mean a bad fuel pump diaghram. Can you take a compression test? What do the spark plugs look like?

 

[racerone]

Re: 88 mercury black max xr4 150

Have the motor test run on a dynomometer to see if it is putting out the proper power !!------------Or have it checked out with a test prop.