80hp Merc Fuel System Problems..I think

[Bo7]

I own an 1988 255 Sprint with an 1988 80hp mercury motor.I can be pegged out going down the river then all of the sudden the boat drops down to about 5-10mph full throttle.I pull the plugs, clean them off and she runs like a top.Usually,the rest of the day.I've also had this problem straight off the dock.Any help would be greatly appreciated.

 

[my new fishmaster]

Re: 80hp Merc Fuel System Problems..I think

Good news for you I had a 90 80hp 3cyl did all the stuff you had mentioned. Its the fuel pump diaphrams being turned over. Unscrew the square pump only 2 screws take appart install new diaphram kit and your back to boating. Could be other things but check this out first. You could try clean and readjusting the fuel pump valves with a toothpick, gets you on the water now.

 

[Bo7]

Re: 80hp Merc Fuel System Problems..I think

Thanks a bunch Fishmaster.Happy Boating!