85 force o/b 85 dies off under throttle

[CATFISH KING]

Re: 85 force o/b 85 dies off under throttle

ok,cool. thought thats what it was... ok, how to "decarbon"? simple as running some chemical thru the fuel, or something else?

 

[john from md]

Re: 85 force o/b 85 dies off under throttle

It is a little more involved than just adding chemicals to fuel. Go to the FAQ in the beginning of the maintenance section and look on the second page.

I suggest that you do the process at least twice in an engine that has never had it done before. Thereafter, just do it at the end of the season and you will keep your engine running strong for a long time.

John

 

[CATFISH KING]

Re: 85 force o/b 85 dies off under throttle

yeah.. i printed decarb intructions last night posted by roscoe and gss036. seems pretty straight forward. hopefully this will resolve most of my performance issues, and my fuel consumption as well. this thing sucks down the fuel! next is to try and get my speedo working and try and get a tach installed too.

 

[john from md]

Re: 85 force o/b 85 dies off under throttle

Tachs can be hard to come by as the older Force engines used 20 pole alternators so you need a 20 pole tach. Modern engines use 6, 8 and 12 pole alternators and the tachs are easy to come by.

For maintenance adjustments, you may look into a company called Sentec or Sendec. They make small ,digital tachs that work off of a spark plug pulse. I have them on all of my small engines and they work well. They mount on the engine so, if you want to see rpm at WOT, you will need someone in the back seat.

A relatively cheap addition you should also consider are Smart tabs. These are trim tabs that automatically adjust without hydraulics. As set for the Bayliners runs under $100 and are easy to put on. They get you up on a plane faster, give you better control in turns and decrease fuel burn. They have a website and you can search these boards for info. Many of us swear by them.

John

 

[mick97]

Re: 85 force o/b 85 dies off under throttle

Hello,

In the decarb faq,it sais something about a fuel plug.
Does a 85 force have a fuel plug?
Not even sure what it is,as im new to the big boating scene

I haven't looked at the motor yet,but plan to this week.
If it does have one,where would it be?

Thanks,
Scotty

 

[CATFISH KING]

Re: 85 force o/b 85 dies off under throttle

ok john, took it out yesterday afternoon. ran about a gallon of mix and seafoam, pulled plugs before i ran it, sprayed seafoam in all 3 cylinders, let it sit for about on hour, started it up, smoked like a freight train, compression checked about the same. sprayed again, took it to the lake, ran about a gallon of mix and seafoam... started fine, idled better than last year, runs good to about 1/2 throttle, still not breaking plane at this point, but begins to sputter past 1/2 way... but stabbed the gas hard once, and it picked up full speed, broke plane and took off for about 20 seconds then died back off... squeezing the bulb has no effect and is good and firm.. do i need to take the carbs off and clean them? or do they need adjusting? or is this something else?

 

[CATFISH KING]

Re: 85 force o/b 85 dies off under throttle

mick97... i don't know the "fuel plug"... in what context was it used? i just decarbed mine yesterday... first time boater too.... was amazed at the carbon the blasted out into the tub.. chunks of the stuff.

 

[mick97]

Re: 85 force o/b 85 dies off under throttle

Catfish,

Congrats.Still awaiting my victory...lol

In the FAQ section,2nd page,under decard it says part way down about the fuel plug.
Wasn't sure if I had one,or even what is was.ha

Guess I can just try it by hooking up a gasline to a gallon jug,and doing as it tells to.
Scotty

 

[john from md]

Re: 85 force o/b 85 dies off under throttle

The plug he is talking about is the quick disconnect that goes to the fuel tank on the boats with external tanks. Usually you have a male connector on the tank and a female on the fuel line from the engine. He was saying that, if you buy a three gallon tank, you have to add the male connector because it doesn't come with one.

John

 

[mick97]

Re: 85 force o/b 85 dies off under throttle

John,

Gotcha on that one..lol

I feel stupid because i actually know what your talking about now.
Thanks a million.
Scotty

 

[john from md]

Re: 85 force o/b 85 dies off under throttle

The gallon jug idea will only work if you remove the female fitting from the fuel hose. It has a check valve in it that has to be opened by pushing it on to the male fitting.

I bought a three gallon tank and use it as a spare when I am going on longer trips.

John

 

[mick97]

Re: 85 force o/b 85 dies off under throttle

Gotcha on that one John.
Thanks,scotty

 

[CATFISH KING]

Re: 85 force o/b 85 dies off under throttle

so whats next John?

 

[john from md]

Re: 85 force o/b 85 dies off under throttle

Chances are that your issues at higher throttle settings have to do with varnish in the main jet and flow path and maybe improper float height. If you don't need the speed, as if you use the boat for fishing, try running it awhile like it is but add four oz of seafoam to each tank of gas. It may clear out by itself, I've seen it happen before. You can also try opening the mixture screws another 1/2 turn. If it clears itself out, you will need to reset them to about 1 turn out.

If it doesn't, then you'll have to pull the carbs and clean them out.

Let me know what happens.

John

 

[CATFISH KING]

Re: 85 force o/b 85 dies off under throttle

I run 6 gallon tanks, so 4oz per 6 gallons of fuel/oil right? or something different?

 

[john from md]

Re: 85 force o/b 85 dies off under throttle

4 ounces to a 6 gallon tank is what I use to maintain my engines and the carbs stay clean all season.

John

 

[mick97]

Re: 85 force o/b 85 dies off under throttle

Well i did a decarb today,and did it 3 times and it still was smoking.lol

Tried it out anyways,and it still takes off for 3-5 seconds WOT and then boggs down.Slow it goes good,but WOT it will not keep.

If i run it where it goes ok at the top speed,and then WOT it,it boggs down immediately.
But if i just go real slow for 3-4 minutes,then open it up,is the only way I can get it to go full throttle for 3-4 seconds.

I did blow through the gas line to see if it was clogged,and it seemed ok.

Prop does have a little damage to it,but I wouldn't think that would hurt too much.

Any new ideas?

Thanks,
Scotty

 

[john from md]

Re: 85 force o/b 85 dies off under throttle

We have been treating this as if it is a fuel problem. It may be you are losing a cylinder when you advance the trottle. When you advance the trottle, it turns the trigger coils to advance the spark. If you have a wire that is making and breaking, it could be killing a cylinder.

You will need help to do this next step.

Have someone drive the boat and you, using an inductive timing light, move the clamp from cylinder to cylinder to see if all three are firing when the engine backs off from WOT.

I'm afraid I am running out of ideas.

John

 

[mick97]

Re: 85 force o/b 85 dies off under throttle

Oh boy.ha

Im not good at things like that.Not sure what to do.
I may end up taking this to a mechanic after all.
Or mabe i could hire one to come over and test it.

Guess it could be a number of different things.
It did backfire,or rather sput-pop the first time i tried to start it.
Mabe the fuel diaphram is broken.
Guess im not too smart on some of these things.

Mabe reeds too?

If its not getting spark to one cylinder,then a coil is bad?
It could actually be lack of fuel like you said,or a cylinder not firing.

Scotty

 

[john from md]

Re: 85 force o/b 85 dies off under throttle

It could be anything but at this point, without further troubleshooting, we are playing guessing games.

What I suggested is not rocket science. An inductive timing light costs $40 at sears. All you need is the basic timing light with no advance. It hooks up to a positive wire and a negative wire and the inductive clamp you just squeeze together, put it over a spark plug wire and release. The power wires can be hooked to the solinoid which is right in front of the starter.

You have to at least investigate a possible ignition problem if for nothing else than to eliminate it as a cause.

Unless you are making a seven digit salary, mechanics are too rich for your blood and they get paid by the hour, not from results. $60 -$80 an hour sure buys alot of gas.

John