18.5 Briggs floods

[metalhead63]

I just joined because I am at a loss. Please help!!
I have a JD Z mower with 18.5 B/S that has a Nikki Carb with solenoid, and a fuel pump. Gas freely flows from tank, through fuel pump, carb and into cylinder. I have done this:
1. removed/disassembled/cleaned carb (no, it does not have a needle valve seat)
2. replaced solenoid.
3. replaced fuel pump.

Only way fuel does not flow is because I added a shut off valve. Otherwise it fills cylinder and backs up into air intake tube.

Model 31P707 code 0123 E1

No valve seat, valve seats on the plastic inlet.

 

[Fish]

Post your engine's model/type/code numbers,
Nikkis inlet needles are expensive, but that is leaking and causing your problem.

 

[metalhead63]

Post your engine's model/type/code numbers,
Nikkis inlet needles are expensive, but that is leaking and causing your problem.

But with carburetor removed, fuel flows freely through diaphragm pump, just sitting there, not running.. I have never seen that. It's like, with fuel flowing like that, why have a pump?

 

[Fish]

Well the tank must be above the engine, MTD just gets a deal on many pallets of engines at a time, if the engines have a fuel pump and don't need it, they don't take the time to remove them, they just slap them on the tractor and ship them.

 

[metalhead63]

But this is a new issue. Been running fine. I have never seen fuel flow through fuel pump when not running.

 

[Fish]

Briggs

Here is a blowup of the engine, the inlet needle is ref#105, with a new one of those, and that danged bowl gasket, the cost of parts is already over $30.