'86 125 Force cutting out in higher RMP

[Haywood123]

I have an '86 Force 125 that was running great the other day. I was running for about a mile at 4500 rpms, we stopped and fished for a few hours, then my three year old wanted to take a run around the lake before we left. Everything was going great and then I stopped fast to pick up some trash that blew out of someone elses boat. I started back up and just after crossing 3000 RPM's, the motor started cutting out and in, like it was flooding or loosing spark.
When I got back to the landing, noticed the clamp had came off of the exhaust boot, but it was still in place, however, there was some water in the housing (not sure if it came in through the boot, highly doubt that it did). Would there be enough suction in the carbs to pull water in? Also, there was gas sitting in the black covers on the carbs.
I just had the carbs rebuilt and replaced the powerpacks. The plugs were all clean, the vent to the gas tank was open, and all of my wires were inplace and tight. Could a fuel pump crap out that fast?

 

[maxum247]

Re: '86 125 Force cutting out in higher RMP

You could sure shake up trash that is in your tank that fast, that may get to your carbs, especially if you don't have a fuel filter in your fuel line.

When trailering and/ or the engine is in the up position gas sloshes around and finds it's way out the throat and the overflow in the top of the carb and drips to the cover thus leaving a puddle in the covers.

 

[Frank Acampora]

Re: '86 125 Force cutting out in higher RMP

If the "boot" that you are referring to is the black rubber bellows that routes some small portion of exhaust and water out the back of the engine below the head, (called the idle relief system) THEN:

If the clamp is missing, push the bellows back off the engine leg and remove it. Check inside to see that there is a spring and a plastic flanged collar. The spring holds the tapered end of the bellows into the rear shroud and the collar keeps the tapered end from distorting and leaking. Occasionally this collar melts or distorts causing excessive back-pressure.

If these parts are OK and the bellows does not have any tears or holes in it, then replace it and secure it with a large plastic electrical zip tie--don't worry, usually not enough heat there to melt the zip tie. Now try the engine.

Reason: Usually, if the bellows is leaking, the first symptom is that exhaust gases collect in the hood and the engine stalls at idle. Take the hood off and it runs fine because it is getting enough air.

Even though it is not under much pressure, water can be blown out a leaking bellows along with exhaust gases--this could cause intermittant cutting out at higher RPM--although I have never heard of this problem until now. However, you do have a problem and there is a possible cause, so it couldn't hurt to check the bellows. Who knows? You might get lucky.

Carbs: in addition to normal leakage when the engine is tilted, the reeds do not close immediately when the piston starts to compress the crancase. Therefore, there is always a little "spit-back" through the carbs. This is why the covers are there. So yes even with brand new or rebuilt carbs it is normal to see some gasoline in the covers.

Before you worry about the fuel pump diaphragm, remove the black plastic inlet cover. Remove the screen and check it for crap restricting flow. Also, if you have quick-connect fuel fittings, unscrew the male fitting and check in the hole. Junk collects in the hole and around the spring behind the ball and restricts fuel flow.

Also, a word of caution: DO NOT MIX BRANDS OF GASOLINE unless both are identified at the pump as containing ethanol. Mixing brands with different additived will cause a jelly like substance to form and will clog fuel lines, filters, and carbs. Additionally, as a preventive measure for other problems, install a cheap 3 buck see-through filter BETWEEN the fuel pump and carbs.

Let us know how you made out.

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

The clamp was still there, but had slipped off a bit. I replaced it with a hose clamp, as there really isn't much room to work in there. Didn't really think of the zip tie, but that would have been a little easier.
I did have some sediment in the screen on the filter that I cleaned out, but not really enough to block much. Last year I was thinking I should put and inline filter in and I still probably should while I am thinking about it.
Honestly, the fuel pump rebuild kits aren't very exspensive, is there any risk to putting them it? Seams kind of self explainitory after looking at my clymers manual.

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

Well, I have went through everything and when I got out today, it started right up, the wife parked the truck, the boat idled fine while I waited, then we took off and as soon as it passed 3500 RPM's, it started cutting out. I kept it right around 3500 RPM's until we got to where we were going to fish and then we used the trolling motor. When we went to leave, the motor started right up, cut out when it got to 3500 RPM's again to I drove it in slow and then shut it off while I went to back the truck in (the wife hasn't mastered that yet). I went to start it back up after only sitting 2 minutes and it would start and kill, start and kill, the only way to keep it running was to rev it up with out putting it in gear for a while, almost as if it were flooded. After a few seconds of reving, it idled normal and I was able to get it on the trailer with out problems.
So in a nut shell, it is cutting out once it gets to 3500 RPM's and it is flooding out when it shuts off. I ordered a fuel pump kit from Iboats. It was inexspensive and should be here by Tuesday. Unless anyone can think of anything else I should try, I am hoping this is the cure all.

 

[maxum247]

Re: '86 125 Force cutting out in higher RMP

By cutting out do you mean bogging down or missing on one or more cylinders?

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

Bogging down
It almost acts like it is either flooding out or not getting gas. It's all cylinders. I will hit about 3600 and it will instantly drop to 2400, then back to 3600 and back to 2400, like I am moving the throttle back and forth. If I keep it running under 3500, it runs just fine. I had it happed on a much smaller scale a few years ago, but it ended up being that the bulb was rotting and colapsing when ever there was much suction.

 

[maxum247]

Re: '86 125 Force cutting out in higher RMP

Yeah! I had trash in my tank a couple years ago and the engine would run like crazy to a certain rpm for a while and then start bogging down to idle, look and the blub would be flat. Get it pumped back up same thing over and over. Cleaning the tank curred it.
Then another time did the same thing but was a air leak in the fuel line.

My manual states that low fuel pump pressure would cause a miss at high speed!

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

Here is something I found odd. My buddy just told me that when he ran seafoam in his boat, it started to act just like mine, like someone was hitting and laying off of the throttle. Ironically, this is the first tank, since I bought the boat 6 years ago, that I put seafoam in and when it first bogged down, the thought that crossed my mind, was that the seafoam finally got through the lines and into the motor.

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

Well, I rebuilt the fuel pump tonight, but I really don't think it is the cause of the problem. It wasn't very bad. Thursday I am running a portable 3 gallon of just gas and oil, in hopes that maybe it is just the seafoam. I don't think I can get the carbs any cleaner.

 

[maxum247]

Re: '86 125 Force cutting out in higher RMP

Rebuilding that fuel pump was a good investment! It'll be you towing the other guy in, not the other guy towing you in!

Let us here what happens with the gas change up!
I was thinking about putting that in my tank but I think I'll wait and see what you have to say Thursday!

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

Yeah, that kit was dirt cheap and it isn't going to hurt (unless of course I screwed it up, but I don't see how you could )

 

[bman1bpm]

Re: '86 125 Force cutting out in higher RMP

mine was bogging down around the same RPMs turned out to be a stuck float on one of the carbs. Its easy to take off the fuel bowls and check to make sure everything is ok in there. Even with the stuck float it ran great at idle and all the way up to a certain point then it bogged.

and by float stuck, I mean the guy who had the boat before me must have adjusted the float so it wouldn't open the high speed valve!

 

[ck85abc3]

Re: '86 125 Force cutting out in higher RMP

Keep in mind that since you rebuilt the fuel pump, you have to run the motor for a while on your old tank with the seafoam in it. Then switch to the 3 gallon if the problem is still present. Otherwise you won't be able to isolate the problem.

 

[maxum247]

Re: '86 125 Force cutting out in higher RMP

Is it Thursday yet?

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

It's Thursday! The old man is on his way over and we are getting ready to head out. I bought a new tank and stuck a quick release on it, so after I do a run with the rebuild fuel pump and see it that solved it, I can switch over to the new gas and see if that solves it. I bought a few extra feet of gas line, so I can switch out a few of my gas lines in the engine as well and I bought a fuel filter to stick in the line between the force filter and the carbs. I have my fingers crossed!

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

Bad Gas! It was all new gas and the same oil I have been using since I got the boat. I ran the boat about 5 miles the first day with no issues, added seafoam and then the problem started. Nothing against seafoam, I have had great luck with it in other things, but my Force didn't like it.

 

[maxum247]

Re: '86 125 Force cutting out in higher RMP

Glad to here it's running good!

 

[bman1bpm]

Re: '86 125 Force cutting out in higher RMP

yeah that new ethanol gas sure does gum up fast! My brother said he was at the lawnmower shop and they told him if its not going ot be used in 30 days drain it, they had a jar of what used to be gas there, he said it was solid.

 

[Haywood123]

Re: '86 125 Force cutting out in higher RMP

The new gas was from the same place as the old gas and the old gas was only 3 days old when the problem started. Now I have 26 gallons of 50:1 mixed gas that I am going to have to slowly start putting in my truck and car.