1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

[O.T.Water]

Hi, I rebuilt the fuel pump and went out boating. The engine ran the best since I owned it in all RPM ranges but after a while of cruising(15-20 mins) it started to lose power. I throttled it back and it was only running on 2 cyls. Went along for a few minutes and it cleared up. Went back to cruising speed and it was fine. Took it home and while flushing, it was sputtering again. I took it to the river the next day and it ran terrible, sputtering, MISFIRING. It did catch and run good for a short time but then back to sputtering. One other question. While I had the engine cover off in the water, I noticed water from the river in the bottom of the engine compartment. Is that normal? O.T.

 

[jerryjerry05]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Check the fuel for water.Put in a water/fuel filter.Check the fuel lines for ethanol damage.It causes the rubber to delaminate and clog the system.J

 

[O.T.Water]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Hi, I put a new filter water/sep on two weeks ago along with complete new fuel feed line from tank to motor, drained the filter once and didn't find any water. When I bought the boat the tank was empty so that was the first thing I did.

 

[john from md]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Water in the lower is normal. It drains when the engine is pulled out of the water.

Pull the fuel line and check the screen. It sounds like it is getting crud in it. A plugged or semi plugged vent will give the same symptoms.

John

 

[O.T.Water]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Hi John, I pulled the pickup tube and removed the siphon valve, replaced it with a no valve fitting. The screen in the tube was clear, no debris at all. When it started sputtering I lost fuel supply again at the ball. I thought maybe it was wiring at the terminal bar above the fuel pump because I moved it to rebuild the pump. I wish I could get this thing to run right consistently as I would like to do a decarb. I checked comp also and it is #1@135. #2@105. #3@135. I'll replace the vent tube and see how it performs. Thanks for the input. O.T.

 

[john from md]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

If you lost fuel supply to the primer bulb, then you have an air leak in the ball or downstream of the ball. I suggest that you pressurized the line and ball with low pressure air and see where it is leaking.

John

 

[O.T.Water]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Downstream, meaning between ball and engine, or ball and tank?O.T.

 

[john from md]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Between the ball and the fuel tank inlet. If your ball and line are old, I would go ahead and replace them. Also, look for pinholes in the aluminum pick up tube if you have one.

John

 

[O.T.Water]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

John, that is all new, however I will pressurize the system to see if I have an air leak somewhere. I also used hylomar at all my connections but who knows, I thought I was extra careful. o.t.:redface:

 

[john from md]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

The only people I know who use Hylomar are people who work on British cars or British airplanes. Which are you?

John

 

[O.T.Water]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Worked as a Mercedes Benz, BMW Parts Manager for years, Hylomar is a favorite for techs that work on those vehicles also. Excellent stuff!O.T.

 

[john from md]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

I must be getting old. I forgot the Germans used that stuff too. Good to see another wrench turner on the list.

John

 

[O.T.Water]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Your not alone, we are all getting older. I hope all helpers like you stay on this forum during your non boating season. Us fortunate ones need advise year round and to boot we never need to winterize. O.T.

 

[jerryjerry05]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

30# difference in the middle cylinder will make the motor run bad.
It needs even compression on all three.
Try PowerTune or Seafoam to bring up the compression.
No mater what you do as long as that problem exists you will never get it to run right.Look in the cylinder and see if there is damage.Check the plugs for rust(possible blown headgasket).
There is a reason the cylinder has low comp,carbs out of sinc,something in the reeds,etc.J

 

[O.T.Water]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

Been running powertune since I bought it maybe I've run 25 gallons with powertune. I want to do a decarb, but I never know when it will run good enough to run it WOT long enough to blow out all the carbon. Sometimes it runs great and sometimes not and I don't know if my misfire is fuel related or electrical. I can't do anything till I get that corrected. Plus I don't know if it is one or multiple issues. O.T.

 

[jerryjerry05]

Re: 1988 Force 85hp Rebuilt Fuel Pump Ran Great Then Didn"t

You can put Marvel Mystery Oil and Powertune (PT first)in the cylinders and let them set for a day then turn it over and add more then do it again.About a weeks worth of setting will help a LOT!!!!!Then run it and get it up to temp.Then add more.Then do a comp test.If that won't work then before you destroy any rings or pistons take it apart and clean it the hard way.
The hoses on my engines went bad after the Ethanol.The hoses between the carbs were ok but all the feed lines went bad.J