Fuel Problems

[Prater 75]

First issue with the 416-8. After running it for about 15 minutes today it sputtered and died, worked fine two days ago. I have worked on many V8 engines and pretty much knew the sound of no fuel to the carb. Sure enough the inline filter was empty of fuel. Tank is full with fresh gas, just filled up. I used some WD40 to get a fire now and then to get the vacuum pump primed. Fuel filter is full again and the work continued for about 15 more minutes when it happened again.

Question:

Should the fuel filter be fed by gravity from the fuel tank and then the vacuum pump take over from there, or does the pump pull from the tank through the filter?

I would like to diagnose if I have something clogging the fuel line, or if the vacuum pump has a leak.

Any pointers to a newbie...

Thanks in advance

[Duff 206]

Steven, just a thought here - I think, if the 400-series tractors are like the 300-series, attached to the fuel shut off that goes into the bottom of the tank is a very fine mesh screen inside the tank. If the in-line fuel filter you mentioned as having been dry is located at a point which is below the tank, gravity should have kept fuel going into the filter unless the screen, valve or fuel line between the tank and the in-line filter are clogged. When you added fuel you may have created enough "pressure" with the extra weight of the gas above to force enough fuel through the clog to refill the filter, but when you started the tractor it pumped the filter dry again - the pump needed more gas than the clog was letting through.

I don't know enough about the fuel pump to say if it pumps all the way from the tank, but my guess would be yes, since these tractors will run going up a pretty steep hill.

So that's my humble two cents - hopefully someone with more experience and knowlege will jump in and either confirm or correct me.

If it is a clogged screen, the screen/shut-off (combined unit) is pretty cheap and very easy to replace.

Duff :omg:

[Prater 75]

I believe I found the culprit. Seems the gas I put in the mower had pulled some moisture from the air. I puled out the ZTR and noticed it was almost empty so I filled it with the rest of the fuel from the can. It started acting the same way. I then suspected water in the gas. Pulled out the fuel cup from my flight bag and drained some fuel in, water was present along with some nasty dust particles. It was a rusty red color (red clay dirt here) and had clogged the fuel filters. I clened them up and fuel started flowing again. Stupid ethenol in our gas just pulls moisture from the air...