Force 125HP misfiring, running rough...

[SkiDad]

yes you are right on 28=30 - i have a white engine too and I had to wait until dusk to see mine.

 

[Glastron_V210]

Those marks are pretty good. My engine doesn't have the reference mark plate (Never seen one before), so I found TDC with a screwdriver and a helper rotating the flywheel and marked up the flywheel to a reference I made myself. It worked pretty well.

Chay

 

[fmt2bx]

Those marks are pretty good. My engine doesn't have the reference mark plate (Never seen one before), so I found TDC with a screwdriver and a helper rotating the flywheel and marked up the flywheel to a reference I made myself. It worked pretty well.

Chay

I was pretty lucky to have the marks, I agree, made it very easy. However, like SkiDad the white paint doesn't help much on a sunny day. Can't see them!!! I guess the thinking was that on a sunny day you should be on the water, not fixing your boat, right?

 

[fmt2bx]

Update: Went to the lake today,
Engine started right away but ran a bit rough, Idle Neutral was around 900 RPM, it was at 1100 rpm last night(?).
Got the boat to finally not stall in gear and off I went, the first few seconds, rough. Then it all cleared up and ran very very well at Wot (4800rpm, smooth. Did a few test, 1/2 WOT, 1/3 WOT etc... all very good.
Went from WOT to idle slowly.
800RPM in Gear (great)
1100 RPM in neutral (great)

ran the boat some more, all good.

Came back and let it idle again at 1100 RPM, then slowly the RPM started to decrease all the way to 800RPM, couldn't get into gear without stalling.
Ran motor again at WOT (4800) then idle again.
This time in gear, went from 800 RPM to 500 then stalled. I'd say it takes about 1 minute to see the first decrease in RPM.

So here is where I am today.
Looks like it slowly runs reacher and reacher, that would explain why after idling too long the mptor runs rough for few second while accelerating, too much unburnt fuel somewhere then at WOT it's all good. (Just my .02 here). Driving me insane to try to figure out whats causing this.

Anyway, I have no idea whats going on, I played with mixture for a bit, it is set at 1 1/8 on both carb, which is where it should be.

BTW, No fuel squirting from carbs while idling.

Cheers.

 

[Nordin]

Have you checked the fuelrecirculing system (puddling drain system)? If it is clogged the idling will be bad.

 

[fmt2bx]

Have you checked the fuelrecirculing system (puddling drain system)? If it is clogged the idling will be bad.

Nordin,

Thanks, I was just checking the lines of the recirc system. Can't find a description of system in y manual.
I have removed these 3 lines and they are all clear.




Now here at the bottom, the line is clear but I can't blow through the fitting, only suction.
Like I don't have a descriptive I can't tell if this is normal.
It is acting as if there was a check valve in the system.



thanks again.

 

[Jiggz]

At this point, personally I would recommend checking on the reed valves. If you do it correctly, the most you will ever need to replace is the intake adapter gasket. Now if the reeds are not seating properly anymore, you have the option of just flipping them over and then conduct a test run again. If the problem is resolved then you can completely replace each set of reeds otherwise you can just replace them back in their original position.

 

[fmt2bx]

At this point, personally I would recommend checking on the reed valves. If you do it correctly, the most you will ever need to replace is the intake adapter gasket. Now if the reeds are not seating properly anymore, you have the option of just flipping them over and then conduct a test run again. If the problem is resolved then you can completely replace each set of reeds otherwise you can just replace them back in their original position.

Alright, thanks.

 

[jerryjerry05]

Nothing wrong with the magnet.
Try to take it off of the flywheel.
If it didn't stay on the stator when you removed it then it's good.

The puddle drain system is the dogbone looking thing attached to the block at the end of the hose.
It has a reed valve in there under the dogbone.
The reeds on the dogbone get carbon build up and stop to function and eventually cause the piston rings to carbon and fail.
That takes a while to happen.

If you don't have fuel coming back out the carbs? Then the reeds are probably good.

Still check them.

The plug in connectors were only used a while and dumped because of failure.
The trigger wires are real thin and the connections break easily.
I would take them(plug in connectors) out and use butt connectors.

 

[fmt2bx]

Nothing wrong with the magnet.
Try to take it off of the flywheel.
If it didn't stay on the stator when you removed it then it's good.

The puddle drain system is the dogbone looking thing attached to the block at the end of the hose.
It has a reed valve in there under the dogbone.
The reeds on the dogbone get carbon build up and stop to function and eventually cause the piston rings to carbon and fail.
That takes a while to happen.

If you don't have fuel coming back out the carbs? Then the reeds are probably good.

Still check them.

The plug in connectors were only used a while and dumped because of failure.
The trigger wires are real thin and the connections break easily.
I would take them(plug in connectors) out and use butt connectors.

Jerryjerry05,

Thank you for posting. That is interesting. My manual, (SELOC), only has a very brief description of the recirc fuel system and no diagram for the 125HP.
It just says that over time it can carbon up but the valves are not serviceable!!!!!

Do you know by any chance what is the name of that dog bone looking cover? I am looking for gaskets before taking it off.

If the valves are not serviceable, what can be done?
I cannot find anything on the net about these valves!!!

Thanks again.

Cheers.

 

[Nordin]

The "dog bone" plate is called cylinder drain cover and the gaskets has partnumber F844725 and F847483. BUT they are not available anymore.
They are in the headgasketkit 2875. Maybe FranzMarine have them.
If you remove the cover, be careful with the gaskets. You maybe able to reuse the old if you apply gasket liguidseal/fluid with the gaskets.

The valves are smal stainless steel plates similar to reeds and they normally never fail.
But there is a smal screen behind the plate that can be glogged. This screen must be cleaned up.

 

[fmt2bx]

The "dog bone" plate is called cylinder drain cover and the gaskets has partnumber F844725 and F847483. BUT they are not available anymore.
They are in the headgasketkit 2875. Maybe FranzMarine have them.
If you remove the cover, be careful with the gaskets. You maybe able to reuse the old if you apply gasket liguidseal/fluid with the gaskets.

The valves are smal stainless steel plates similar to reeds and they normally never fail.
But there is a smal screen behind the plate that can be glogged. This screen must be cleaned up.

Just purely AWESOME!!!!! Thank you very much for all the info. Found the gaskets as stand alone gaskets, less than $10.!!!

I had a bit of time so decided to tackle the cylinder drain cover:

Here are some pictures that might help someone one day:

1)-Location of cylinder drain covers:





2)-Front cover removed exposing reed valves:






3)-Reed valves removed:





4)-Back side of reed cover with screen:





5)-Behind the drain cover:

 

[jerryjerry05]

The pics you provided, the parts looked really good.
Hardly any carbon or crud.
The screens are NLA but you really don't need to replace them anyway.
Looks like the reeds and screens aren't part of any problem.
Is it still running bad?

 

[fmt2bx]

The pics you provided, the parts looked really good.
Hardly any carbon or crud.
The screens are NLA but you really don't need to replace them anyway.
Looks like the reeds and screens aren't part of any problem.
Is it still running bad?

I am definitively no expert but I agree, I didnt see anything really bad with the drain reeds or screens. Motor Still running badly at idle.
Next will be the reeds as Jigzz suggested. I was going from the easiest ( for me) things to check to the most difficult.
At least, the fuel recirc system has been checked. .
Waiting on parts to start the reed job.
Thanks a lot for your help.
Cheers

PS: thinking about changing the fuel recirc lines with clear lines. I'd like to see what's going on with that system. Any reason I shouldn't?

 

[Jiggz]

Clear fuel lines with the recirc system is an excellent idea.

 

[fmt2bx]

Clear fuel lines with the recirc system is an excellent idea.

Great, thanks. While I am in there, is there anything else I could do in the fuel recirc system?

 

[jerryjerry05]

Nothing other than put them back.
Install a filter between the carb and the pump.
Fram G2 or G12 (you get Fram in S.A.?)

 

[fmt2bx]

Nothing other than put them back.
Install a filter between the carb and the pump.
Fram G2 or G12 (you get Fram in S.A.?)

Ok thanks. Im in WA, we get fram.
cheers

 

[fmt2bx]

Going to start working on the reeds today.
Question:
Would you use gasket sealer when replacing old gaskets with new ones?
Thanks

 

[Jiggz]

NO need at all. It wouldn't hurt to use though if you wish to do that.