1988 Mercury 115

[Ak1081]

Hey guys so I just recently acquired a bass boat with a 1988 Mercury 115 inline 6. I finally got it running and water tested it a few times. The first time the boat ran great with no issues. The second time the boat began to run good then all of a sudden would not go above 1500 rpm. At that point I took the boat in and replaced the inline filter with a water seporator and replaced the inline filter next to the fuel pump. The last time I took it out it was the same issue. Runs good but only at 1500 rpm, if I attempt to give it more gas the boat stalls out.

 

[racerone]

Check spark.----Sounds like it might be running on 3 cylinders.----Stop running this motor.----If it was a blocked carburetor it would starve 2 cylinders of gas and OIL .-----You should install a new water pump impeller too.----Test the hot horn as well.----Running with 50:1 mix or something else ?

 

[Ak1081]

Check spark.----Sounds like it might be running on 3 cylinders.----Stop running this motor.----If it was a blocked carburetor it would starve 2 cylinders of gas and OIL .-----You should install a new water pump impeller too.----Test the hot horn as well.----Running with 50:1 mix or something else ?

Thanks, the engine seems to be pumping water strong, you think I should replace the impeller regardless? I assumed it had to be a fuel issue, and yes 50:1 I got rid of the auto blend pump that it had and just put pre mix in the tank. I’ll check the spark

 

[racerone]

Those motors need a new impeller about every 3 years.-----Your choice to gamble.----It can be hard / difficult to teach all the novice boaters about maintenance these days.

 

[Ak1081]

Those motors need a new impeller about every 3 years.-----Your choice to gamble.----It can be hard / difficult to teach all the novice boaters about maintenance these days.

Thanks I did not know that, which is why I came to this website for education, no need for the arrogance, yes I am new to this.

 

[racerone]

Wow----Some folks are offended when you tell them like it is.----When I went to school teachers told you you were wrong and deducted marks !!----A different world today.----Good luck with the tower of power.

 

[Ak1081]

Wow----Some folks are offended when you tell them like it is.----When I went to school teachers told you you were wrong and deducted marks !!----A different world today.----Good luck with the tower of power.

I appreciate the help, I thought everyone on here was on the same team, not to be someone’s subordinate

 

[racerone]

I often tell folks to install a new impeller on recent purchases.----Something that has been proven over 50 years of work.-----A very common reply is ---"my water pump is working fine "------Folks just do not realize that many motors do not have an overheat warning horn, or if it actually works !----Most motors will continue to run to destruction should impeller fail !-----Many mechanics will second my seemingly ---" wild opinion " ---on replacing the impeller on a tower of power every 3 years !-----Found 2 impellers on 70 HP motors recently that had been run dry.----The new owners did not realize that seller fired up the motor at the end of the driveway without cooling water to the impeller !

 

[roscoe]

Its always a YES answer on changing the impeller.
Good to know it is new and working, and its cheap.

These motors do have an overheating history.

They do not have a thermostat, max cooling water flow needed at all times.

OH, a quick note on the forums.....
Its very hard to detect voice inflection and, tone of voice, sarcasm, on the forums. Very much like misreading a text on your phone.
Factor in a missed word, or punctuation mark, and the meaning can very easily be misconstrued. So don't be offended, keep a cool head, and send me a couple dollars to put toward my next boat. LOL