Help Diagnosing Issue

[MrLarkins]

Okay good. When it goes to die, will giving it a bit of choke help at all?

yes! I can drive it for another few minutes on FULL choke.

 

[VegetiveSteam]

yes! in can drive it for another few minutes on FULL choke.

In the video it sounded like it was either starving for fuel or getting air it shouldn't be getting. Either way it seemed lean to me. But that's just one opinion.

If that engine has a plastic intake manifold, they have been known to separate at the seam and also leak at the o-rings where it mounts to the heads.

It's only a theory but if the intake manifold was separating, it may need to get warm before the crack opens up to the point it lets in enough air to cause issues. Once the engine slows, the governor would open the throttle plate wide open and I wonder if at that point it's able to suck some more fuel until the governor reacts and lets the throttle plate start closing again and it just keeps repeating itself until the crack opens up to the point even choke doesn't help.

This wouldn't explain some of the other issues you have going on but it could account for part of it.

 

[MrLarkins]

It is plastic. How can I test your theory?

I've attached some images of the manifold. the seem and top dead center...take a close look.

 

[VegetiveSteam]

It is plastic. How can I test your theory?

I've attached some images of the manifold. the seem and top dead center...take a close look.

Carb spray. When it starts acting up, carefully spray the seam and the ends at the head.

 

[MrLarkins]

Carb spray. When it starts acting up, carefully spray the seam and the ends at the head.

ok, done. ran it, and when it started to die, I sprayed the seams...no effect. I then sprayed some carb cleaner directly into the air box, and the engine picked right up and rev'd, for a moment anyway. Should I take apart the carb again and take a closer look?

 

[bertsmobile1]

yes! I can drive it for another few minutes on FULL choke.

This is text book floating debris in the fuel tank blocking off the fuel supply
Next time it stops pull the fuel line off on the tank side of the pump ( if fitted ) and blow back through the fuel line.
If the engine fires right up them either the tank needs a clean or the fuel line has degraded & needs replacing .

 

[MrLarkins]

This is text book floating debris in the fuel tank blocking off the fuel supply
Next time it stops pull the fuel line off on the tank side of the pump ( if fitted ) and blow back through the fuel line.
If the engine fires right up them either the tank needs a clean or the fuel line has degraded & needs replacing .

how will the fuel filter affect this attempt?

 

[VegetiveSteam]

Once it gets bad enough that it dies, will it start right back up?

 

[bertsmobile1]

how will the fuel filter affect this attempt?

I just makes it harder for you to blow back.
The fuel pump ( where fitted ) has 1 or 2 check valves so you can not blow back through it from the outlet side

 

[MrLarkins]

Once it gets bad enough that it dies, will it start right back up?

yea, but it won't last