1998 Force 120 Stalls out in Low Gear

[L3af]

Hey Guys,

Having some ongoing issues with my Force.

Here's the summary:

Motor was dying at low RPM when shifting into gear. Then:

-Motor started not only dying at low speeds, but high RPM.
-I'd push the throttle and it would just die.
-Would start up and idle fine.

Today I went out and

-Motor wouldn't start at all.
-Hooked up an external tank and after 2-3 mins of cranking it over, it started, idled and when throttled ran great.
-On the way back to the dock the motor died out at low RPM's (On the external tank still).

Some #'s

Motor idle speed is set at 800 RPM.

Compression tested last year:
Cylinder 1 - 130
Cylinder 2 - 145
Cylinder 3 - 150
Cylinder 4 - 135

What should be the plan of action from here?

I was thinking running a bottle of Marine Seafoam through it and checking the Fuel/Water Separator.

After that, what's the best way to check if fuel lines need to be swapped and if the fuel vent is blocked/not working?

 

[Nordin]

Change the fuel pump diaphragm and put a clear cheap inline fuel filter between the fuel pump and the carbs.
This is cheap stuff and useful.
With a clear filter you can see if fuel is pumping to the carbs the troubleshoot from there.

 

[L3af]

Change the fuel pump diaphragm and put a clear cheap inline fuel filter between the fuel pump and the carbs.
This is cheap stuff and useful.
With a clear filter you can see if fuel is pumping to the carbs the troubleshoot from there.

Beautiful.

Is the fuel pump diaphragm a gasket?

 

[topgun3690]

Beautiful.

Is the fuel pump diaphragm a gasket?

No.....is not a gasket. The one for mine looks like this.....I believe the one for yours is more square shaped, but works the same way.....

 

[L3af]

View attachment 386470No.....is not a gasket. The one for mine looks like this.....I believe the one for yours is more square shaped, but works the same way.....

Got it.

Will any of these in-line clear filter works?

Part number the Force Manual says is: 35-816296

General PDP Template

www.canadiantire.ca

Currently I have a opaque white one. Ordering a clear one from the boat store will take a week or so.

 

[topgun3690]

Something like this Fram G2 works well.....they make different ones for different fuel hose sizes.....the clear one you ordered will probably be ok...you don't really need an expensive filter as it is mainly for visually seeing the fuel flowing, not so much for filtering.

 

[Nordin]

Yes exactly what Topgun3690 says, use those cheap filter such as Fram G2 and other brands.
BTW Fram is a good brand in my opinion, they make good oil filters for cars and these fuel filter are very good stuff.

 

[racerone]

What are the compression numbers today ?----Water pump impeller replaced ?-----Overheat horn tested ( if equipped ) lately ?----Spark on each cylinder that jumps a gap of 3/8" or more ?

 

[L3af]

What are the compression numbers today ?----Water pump impeller replaced ?-----Overheat horn tested ( if equipped ) lately ?----Spark on each cylinder that jumps a gap of 3/8" or more ?

Not sure on compression today, it's in the water right now so hard to test.

Impeller hasnt been changed but the tell tale is strong.

Dont believe it has any overheat horn etc.

It dies at low idle on the external tank so I'm guessing it's something to do with the idle RPM? carbon build up? What do you think?

 

[racerone]

Parts list seems to show a temperature switch.

 

[L3af]

Parts list seems to show a temperature switch.

Interesting. I don't have a temp gauge so I'd have no idea where to look for this.

Also wouldn't it shut off at high RPM's if it was the temp switch?

Sorry, this is my first outboard so I'm trying to learn!

 

[L3af]

View attachment 386475Something like this Fram G2 works well.....they make different ones for different fuel hose sizes.....the clear one you ordered will probably be ok...you don't really need an expensive filter as it is mainly for visually seeing the fuel flowing, not so much for filtering.

Closest I can find in Canada is this:

https://www.amazon.ca/Zemoner-Filters-Replaces-Kawasaki-Stratton/dp/B088R6GRMW/ref=sr_1_7?crid=2SZTQAN67F6VI&keywords=Fuel+Filter+5%2F16%27%27&qid=1691082146&sprefix=fuel+filter+5%2F16%27%27%2Caps%2C422&sr=8-7

 

[topgun3690]

Closest I can find in Canada is this:

https://www.amazon.ca/Zemoner-Filters-Replaces-Kawasaki-Stratton/dp/B088R6GRMW/ref=sr_1_7?crid=2SZTQAN67F6VI&keywords=Fuel+Filter+5%2F16%27%27&qid=1691082146&sprefix=fuel+filter+5%2F16%27%27%2Caps%2C422&sr=8-7

ebay Canada has the Fram.....they also have the Fram knockoff brand GKI.....Have been using the GKI for a while, no problems.....you can get multi packs of them pretty cheap.

 

[topgun3690]

Interesting. I don't have a temp gauge so I'd have no idea where to look for this.

Also wouldn't it shut off at high RPM's if it was the temp switch?

It is a thermoswitch, not a temp sender.....when the engine reaches a certain temp the switch activates and turns on the warning buzzer.....the engine will not shut off automatically....YOU have to shut it off when you hear the buzzer. #18 in the diagram.....

 

[L3af]

It is a thermoswitch, not a temp sender.....when the engine reaches a certain temp the switch activates and turns on the warning buzzer.....the engine will not shut off automatically....YOU have to shut it off when you hear the buzzer. #18 in the diagram.....View attachment 386531

Never have heard the temperature alarm. So I assume it's not this.

 

[topgun3690]

It's a good thing you haven't heard the buzzer for real.....usually the damage is already done when you hear it..........is mounted on the cyl head near one of the spark plugs....held in by a retaining clip....

 

[L3af]

It's a good thing you haven't heard the buzzer for real.....usually the damage is already done when you hear it..........is mounted on the cyl head near one of the spark plugs....held in by a retaining clip....

Yeah I've been thinking about adding a temperature gauge.

Today I fixed the fuel sender which was put in all wonky.

Definitely could have been an air leak there, which would explain the issues running poor on the internal tank but (mostly) fine on the external tank.

What RPM's do these motors normally idle at in the water?

 

[topgun3690]

Yeah I've been thinking about adding a temperature gauge.





What RPM's do these motors normally idle at in the water?

I added a temp gauge.....but maybe should have gone with a water pressure gauge instead. Lots of opinions out there on that....
The linc n sync stickie by the late Frank A. says to set idle rpm to 700-750 in the water in forward gear....my manual says the same IIRC.

 

[jerryjerry05]

Temp/overheat-gauges or alarms?
The thing about a gauge is you don't watch them all the time, if you do? Myself, I'd get seasick.
Fix is a louder horn, car or motorcycle horn and put where you can see/hear them.
A pressure gauge just tells you it's pumping but won't say anything if it quits, again watching the gauge, you don't do.
A BRIGHT light on the dash is also a way to go. When it glows it's getting hot.
My opinion: a louder horn and make sure it's wired right(can be wired backwards and nothing happens)) is the way to go.

 

[topgun3690]

Temp/overheat-gauges or alarms?
The thing about a gauge is you don't watch them all the time, if you do? Myself, I'd get seasick.
Fix is a louder horn, car or motorcycle horn and put where you can see/hear them.
A pressure gauge just tells you it's pumping but won't say anything if it quits, again watching the gauge, you don't do.
A BRIGHT light on the dash is also a way to go. When it glows it's getting hot.
My opinion: a louder horn and make sure it's wired right(can be wired backwards and nothing happens)) is the way to go.

Years ago was cruising at high rpms when suddenly the engine quit....only then could I hear the buzzer.....way too late. After a PH rebuild, added a louder horn, temp gauge, and light on the dash....and test them regularly.