Boat cuts out when throttling up

[Sugarbug]

Ok, so I'm at the end of this AWESOME boat project. Plugged the gas line in after installing a new bulb and small inline fuel filter (this one) and the motor cranked right up! Was very pleased about that as it is thirty-something years old and has been sitting for about 4 months.

When I crank it on it does fine, but if I start to throttle up it cuts out. It's acting like it's not getting enough fuel and the first thing I thought of was the in-line fuel filter. Perhaps it is too restrictive or just too small to accommodate the fuel needed at higher rpm? Thoughts?

 

[kpm]

Maybe carbs are gummed up?


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[carlosd321]

I had that issue and thought the same thing. My issue turned out to be the jet on the carb would get clogged because there was trash in the bowl. Of course I did not know that until I broke the carb down and that was after I replaced the fuel lines, tank, filters, etc. That ethanol fuel really messed some stuff up because I let it sit. You mentioned yours sat for four months so if you havent already I would deffinately look at the carb

 

[Gunnut80]

Yeah, sounds like carb issue or could be related to a coil braking down under a load. Try running some Seafoam through it. I always run some ethanol treatment in the gas otherwise that stuff will wreck your fuel system.

 

[Sugarbug]

Don't really know what I'm looking for. The carb looks good. It's functioning. There is a valve in the front (all the way open) and a valve behind that is closed. The rear valve starts to open as I throttle, but then it dies immediately.

Also, I'm getting white smoke out of the exhaust. Is it running too lean? I used a 32:1 mixture for the 2 stroke oil to gasoline. It is ethanol gas (the only place I found that is supposed to have ethanol free gas has been recently demolished).

 

[smith625]

Your high sped is plugged and you should be running 50:1 oil fuel ratio. Tell me what motor and hp and i can guide you better.

 

[Sugarbug]

It's an old (70s) 35hp Johnson outboard.

 

[carlosd321]

You would actually have to break the carb down. You would be suprised at how small a particle can be and cause issues. When you do you will be able to see a film like discolored coating from the fuel and all that would need to be cleaned. Like someone else said try seafoam and if it helps at all then you know where your issue is. The only other thing I can say is look for leaks or pin holes in your lines. When you throttle if air is being sucked in somewhere this can cause it to sputter and die. Thats about the extent of my knowledge. You can try mud motor talk, some really good guys ont here who can provide good info.

Don't really know what I'm looking for. The carb looks good. It's functioning. There is a valve in the front (all the way open) and a valve behind that is closed. The rear valve starts to open as I throttle, but then it dies immediately.

Also, I'm getting white smoke out of the exhaust. Is it running too lean? I used a 32:1 mixture for the 2 stroke oil to gasoline. It is ethanol gas (the only place I found that is supposed to have ethanol free gas has been recently demolished).

 

[VeedUp]

Sounds like carbs, which have been said already. Try running some sea foam through it, if that don't work you may need to rebuild the carb.

 

[smith625]

Sounds like carbs, which have been said already. Try running some sea foam through it, if that don't work you may need to rebuild the carb.

This often works and try tapping on the bowls when it is running.

 

[Sugarbug]

where can I pick up sea foam? Wal-Mart? Advance auto?

 

[kpm]

Wal mart auto zone. About $8 and some change


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[Sugarbug]

Your high sped is plugged and you should be running 50:1 oil fuel ratio. Tell me what motor and hp and i can guide you better.

I tried looking online for the proper mix ratio and I found between 26:1 and 32:1. Why 50:1? I can't find the stupid manual for this thing :S Will too high a mixture create problems?

 

[smith625]

It is just hard to keep the plugs clean with that much oil and the performance will be down some as well. 50:1 is what i remember using in those motors.

 

[carlosd321]

I have always used 50:1 just what I was told. This is what my bowl looked like when I broke mine down, its supposed to be silver. I blame most of it on ethanol but I let it sit. If yours has been sitting you should really have it cleaned out and always run fuel treatment (STABIL) in your fuel.

I tried looking online for the proper mix ratio and I found between 26:1 and 32:1. Why 50:1? I can't find the stupid manual for this thing :S Will too high a mixture create problems?

 

[Emperor]

Before you do all that stuff, make sure there is no air leak anywhere in the fuel line from tank to adaptor. Inspect the fuel adaptor carefully. If the rubber seal housing the ballbearing is worn/old, you could have air leak. This will cause the motor to sputter.

Also, the priming balls can have small cracks when they sit up or get exposure to the sun. If you have a good air tight seal, then move on to carburaetor repair.

Outboards, like computers; start with the most basic logical point of problem, then work toward the hard stuff.

 

[Sugarbug]

Here are a few shots with the air cover off. Tell you anything?

 

[carlosd321]

is your fuel line dry rotted? When cut into it for the filter did trash come out?

 

[Sugarbug]

No it was fine.

 

[Gus McCrae]

Just a thought to add. Did you let the engine warm up before giving it throttle? Sometimes, they run a little too lean at startup..... especially if the choke is off.... especially in cold weather.