Fuel leaking from foot 1986 50 hp Yamaha

[markpatty72]

Fixed fuel leaks in carbs and fuel lines. Fuel is now leaking from the bottom of the foot. With engine slanted so any leaking fuel has to come out front of carbs, there are no leaks from carbs.
No visible leaks in engine compartment. Does that leave only the fuel pump as the source? Can the fuel pump somehow leak into the area where the drive shaft goes to the foot?

 

[racerone]

I would say that the diaphragm in the pump is ruptured.

 

[QBhoy]

You sure it’s fuel and not 2 stroke residue…or gear oil ? Are you seeing this in the water or on trailer whilst running it or when not running?

 

[markpatty72]

You sure it’s fuel and not 2 stroke residue…or gear oil ? Are you seeing this in the water or on trailer whilst running it or when not running?

On trailer while not running but while squeezing the fuel tank bulb. It definitely is fuel.
After further research I’m thinking fuel pump internal leak.

 

[markpatty72]

I would say that the diaphragm in the pump is ruptured.

If the diaphragm is ruptured and fuel is making it to the foot, are there any seals from where the fuel is leaking to the foot that might be bad?
Or is it change the fuel pump and float the boat?

 

[fatlenny]

now im one year new to owning an outboard motor but from what i do know about carburetors (many years of other small engine work and experience) and have learned with the outboard I have is that the float only holds the needle against the seat in a fairly level position. when you raise the motor all the way up, the fuel in the bowls will pour out the front of the carbs and run where ever it can.

 

[markpatty72]

now im one year new to owning an outboard motor but from what i do know about carburetors (many years of other small engine work and experience) and have learned with the outboard I have is that the float only holds the needle against the seat in a fairly level position. when you raise the motor all the way up, the fuel in the bowls will pour out the front of the carbs and run where ever it can.

Good to know. I do raise the motor all the way up for travel. That might explain fuel in carb cover and fuel running where ever.

 

[fatlenny]

Good to know. I do raise the motor all the way up for travel. That might explain fuel in carb cover and fuel running where ever.

If you have no leaks in the lowered position, I would think this is what is going on. pump up the primer bulb in the lowered position and you should feel it harden up when all the bowls are full. you can overpower the needle and seat by hand but you should be able to tell if you have an issue or not.

 

[markpatty72]

If you have no leaks in the lowered position, I would think this is what is going on. pump up the primer bulb in the lowered position and you should feel it harden up when all the bowls are full. you can overpower the needle and seat by hand but you should be able to tell if you have an issue or not.

I tested each carb before installing them while hooked directly to the bulb line and they all held pressure.
When I hooked them all up to the fuel line and pumped fuel through the fuel pump the fuel started leaking out the foot.
Im pretty certain it is internal fuel pump leak.

 

[markpatty72]

Barring any other ideas, I will install a new a fuel pump.
Thank all your inputs and for the education!

 

[fatlenny]

Barring any other ideas, I will install a new a fuel pump.
Thank all your inputs and for the education!

Barring any other ideas, I will install a new a fuel pump.
Thank all your inputs and for the education!

your welcome, but if I am understanding you correctly, you are only having this issue when you have the motor lifted. If you dont have this leaking issue when in the lowered position, I dont believe you have any issue with the pump.

 

[racerone]

A few $$$ for a new diaphragm might do the trick.----But if money is not an issue then a complete new pump will do the trick.----I usually inspect stuff before throwing parts at a motor.

 

[markpatty72]

your welcome, but if I am understanding you correctly, you are only having this issue when you have the motor lifted. If you dont have this leaking issue when in the lowered position, I dont believe you have any issue with the pump.

My apologies for insufficient details. It leaks when the motor is not lifted. Good thinking on your part though.

 

[markpatty72]

A few $$$ for a new diaphragm might do the trick.----But if money is not an issue then a complete new pump will do the trick.----I usually inspect stuff before throwing parts at a motor.

After much review of junk that is out there, the idea of being dead in the water with grand kids on board inspires me to find OEM part. OEM Part is on order.

 

[markpatty72]

The culprit is installer error as visible on the diaphragm in the upper right screw hole.
The boat has not been used by me yet. Bought it with multiple fuel line leaks. Hopefully this is the last fuel leak and I can get the boat in the water. New fuel pump has been shipped.