85 Force 125 won't idle

[jerryotis]

Took this project boat out last weekend to play for a couple days and run a tank of fuel through it. I bought it and it hadn't run for 3 years. I was able to use it to pull skiers and a tube but it definitely has some issues.

The start sequence goes like this, throttle all the way forward, choke, and crank. It will pop, release the choke and grind a bit until it fires up. It will NOT idle in the neutral position. You have to keep it throttled.

It won't idle in gear or in between reverse/forward, you have to go to neutral safety and keep it throttled. You can't low speed move (like in loading on the trailer) it just dies.

As I said, it runs pretty well on acceleration, but does have a bit of a stumble. It clears up and accelerates fine and runs perfect at speed.

I brought it home and pulled the carbs off, fully expecting to find all sorts of gunk but they were actually pretty clean. I used aerosol carb clean and blew out all passages, check the needle and seats for wear, checked the idle/air needles for wear, adjusted the floats and put them back on. I synchronized the carbs, adjusted the throttle plate/eccentric, and set the air/fuel needles to 1 1/8 turns out. Fired it up and still won't idle. The bottom carb is running fuel out the throat and the little brass bleed hole on the port side of the carb body, just behind the fuel line tee. I rechecked the float and it is fine. The top carb seems fine.

What do I have going on here? Is my fuel pump overcoming the needle and seat, or is there an internal problem with this carb? TIA for any help. I have watched all the videos I can find and haven't seen this issue.

 

[Jiggz]

Since there is fuel overflowing out of the carb bowl vent hole, this is an indication either the float switch is not adjusted correctly or the inlet needle or seat is not sealing properly.

Fuel blowing out of the carb's mouth is an indication of above or it could also be a reed problem. A broken reed will prevent the motor from properly idling.

By checking the condition of the #3 and #4 spark plugs and compare them with the #1 and #2 should tell you which cylinder is not firing properly. Better yet, clean and dry all plugs, re-install and ran for a few seconds and then re-inspect plugs again. Usually, a non firing plug will be wet and clean as a whistle. Or it could also be dry and clean as a whistle especially if you have a broken reed.

 

[jerryjerry05]

Make sure the diaphragm is ok.

 

[jerryotis]

Am going to check the diaphragm tonite but here is a pic of the carb and where the gas squirts out of. The little brass fitting with the hole in it.

 

[Jiggz]

Yes that little hole is the bowl vent and if the inlet needle doesn't close properly, either improperly set float or rough needle or seat, fuel will overflow.

You can do a simple test by removing the bowl and disconnecting the top fuel line from one end (top carb). Disconnect the bottom fuel line from the carb. Cover the bottom fuel line connection with one finger, blow lightly into the top fuel hose while raising and lowering the float.

With the float in up position you should feel great resistance with your blowing if it closes properly.

 

[jerryotis]

Yes that little hole is the bowl vent and if the inlet needle doesn't close properly, either improperly set float or rough needle or seat, fuel will overflow.

You can do a simple test by removing the bowl and disconnecting the top fuel line from one end (top carb). Disconnect the bottom fuel line from the carb. Cover the bottom fuel line connection with one finger, blow lightly into the top fuel hose while raising and lowering the float.

With the float in up position you should feel great resistance with your blowing if it closes properly.

Good idea! I went ahead and ordered two new floats and a fuel pump diaphragm and will see what happens after that!

 

[Jiggz]

Should have done the testing first before ordering parts.

 

[jerryotis]

Should have done the testing first before ordering parts.

Yes but it has the original old floats in it and while they may be ok, can't hurt to replace them with the newer versions that don't get fuel logged.

 

[jerryjerry05]

The new floats: you see a pic of them?
Some come with no way to adjust them?
Post a pic of the old.
The only ones that become saturated seem to be the brass ones.

 

[jerryotis]

The new floats: you see a pic of them?
Some come with no way to adjust them?
Post a pic of the old.
The only ones that become saturated seem to be the brass ones.

Yeah, I just found that out! The oem floats are the foam type. The replacement are the plastic ones and are not adjustable. In any case, I believe that I found the real issue depending on how you or someone else answers this question. My carbs have the press in seats and I looked down in them and found a green rubbery substance. It looks like they have a neoprene seat of some sort, is that right? If so, it is coming apart in both carbs. I picked the loose pieces out but if they are a seat lining or something I know that I am not getting a good seal. Everything I read says the press in seats are not replaceable. The needles are not showing any wear. Any thoughts?

 

[jerryjerry05]

The green could be the rubber seal??

Some have had minor luck when trying to replace the seats

The additives, cleaners, pre-soaks, maybe even Seafoam turns the seal into jelly.
You can wash with Dawn soap and water and then let dry for a couple of days.
The rubber eventually gets hard again.

But, IF??? one TINY piece is missing it probably won't work.

The needles, there are 2 types: #1 is a solid needle. #2 is a needle with a rubber tip.

#1 usually not a problem.
#2 the tip gets a groove and that turns it useless.

Sent you a PM.

 

[jerryotis]

Mine are the solid needles and I inspected them closely, no wear groove on them. The green material really seems to be a seat of some sort. I can't find any reference to them in my manual or any posts I've searched so far. The only thing my manual shows is the difference between a seat with a bevel and one without. Perhaps the one with the bevel is the one with the neoprene seat, I don't know. I'm not really interested in trying to replace the seats as that would probably not go well. I may try to dig out all the material and see if the needle will seat against the brass itself BUT the needles may be too short then! Got nothing to lose at this point!