Fuel ball collapses

[Bozol]

Hello,

I've replaced my fuel line and ball, the gas tank vent is clear and I'm currently running with the fuel-water separator disconnected. Despite all this after about 1 hour of high rpm use the fuel ball is collapsing and my engine gets bogged down. Speed drops from about 35 mph to around 28 and is really long to get up on a plane. After the engine rests for a while (10 minutes or so) the problem is solved for about 5 minutes then comes back.

Running a V4 Johnson 90hp, 1992 (2 stroke)

Any ideas?

Thanks,

Bozol

 

[ezeke]

Re: Fuel ball collapses

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[F_R]

Re: Fuel ball collapses

Definatly a restriction between the primer bulb and tank. It is a must-fix item, as running lean on gas can destroy the powerhead.

 

[jtexas]

Re: Fuel ball collapses

yup, check for debris in the tank, replace fittings and primer bulb too, if you haven't already done so recently, they will wear out over time. Spend the extra $7 or so on the BRP name brand primer bulb.

 

[Bozol]

Re: Fuel ball collapses

Thanks for your answers.

The fuel ball and associated fuel line are brand new. The tank is a custom build under the seat; the connection from tank to engine is only 2 ft.

What is an 'anti syphon' valve and where would I find it?

Can I just drop the fuel line (with pump attached) into the gas tank without the exit valve?

Could it be a bad fuel pump?

 

[ezeke]

Re: Fuel ball collapses

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[Bozol]

Re: Fuel ball collapses

The fuel line starts at the gas tank just above the height of the engine connection, however it does drop to the floor of the boat between them. I will check the valve tonight. Are they easy to clean/replace? I live in a very isolated community (Canadian Arctic - Inuvik) and might not be able to find specialized stuff.

Bozol

 

[ezeke]

Re: Fuel ball collapses

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[jeeperman]

Re: Fuel ball collapses

Did the problems start only after you changed all those parts in your first posting?

 

[Bozol]

Re: Fuel ball collapses

The problems have been consistent since I bought the boat a month ago. Doesn't matter if the new or old parts I've worked with are in. When the guy sold me the boat he thought the fuel pump was done; turns out he didn't have the pressure line connected to the crank (VRO pump). I think the pump is fine and the engine goes great when getting enough gas.

Why?

 

[jtexas]

Re: Fuel ball collapses

its the pump pulling against an obstruction that makes the primer bulb collapse - if the pump weren't sucking hard enough it (the bulb) would go soft.

another possibility is an obstructed vent - if the tank's not vented, you get a vacuum in the line which the pump eventually can't overcome.

could also be something in the tank blocking the inlet hose then floating clear when the engine stops.

 

[uniquesound]

Re: Fuel ball collapses

my brother in law had the same problem in his boat. It turned out that when he changed his sender the gasket sealer he used was not gasoline proof so it got gummy and clogged up the supply hose in the tank causing the bubble too colapse from the suction! we figured this out by running the boat with an auxillary tank.

 

[samo_ott]

Re: Fuel ball collapses

Whay happens if you run it with the gas cap off?

 

[Bozol]

Re: Fuel ball collapses

No difference with the gas cap off.

Had the anti-syphon valve replaced with a regular valve and the ball, while never rock hard (to be expected), is not collapsing and the engine is running pretty well.

 

[DaMightyWackO]

Re: Fuel ball collapses

I had the same problem last weekend, fuel ball totally vacuum.
The internal hose that goes from the tank top to the bottom sucked itself on my just installed fuel level sender. (Of course all the doom scenarios went through my head first before i discovered why my engine suddenly stopped )

 

[ezeke]

Re: Fuel ball collapses

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