[raboley]

My sons 318 was actually a great starter and running machine. He was tooling around the yard about a week ago, and it suddenly sputtered and died. I ended up cleaning the carb (top side only), added fuel filter before carb and made sure gas in tank. I mowed with the it last night and did great. When I started it tonight, it started and then sputtered and died. I could tell from the fuel filter it was not getting fuel. Cranked a couple minutes, it started and I mowed half an acre with no issues.

More info: I had previously replaced the fuel gauge since it looked like it was crumbling.

I have 3 theories:
1. Fuel pump slowly going bad - replace
2. Fuel pump has vacuum leak - fix leak
3. Gunk from tank plugging fuel pump - clean gunk and put another filter before pump

Thoughts?

 

[ben12]

Richard; I would start by removing the fuel tank and cleaning it out really good;remove and replace the reserve line in the tank,and clean the main fuel pick-up,replace the tank bushings;and replace all fuel lines and the filter.This will either fix that problem or eliminate any further problems due to dirty tank or deteriorating fuel lines.Once this is done you might think about an ethanol enzyme additive like Startron. Good luck Ben

 

[Hammerdown-7]

Hello Richard
Ben makes some very vital point's here this Ethanol has been rotting the inside of rubber fuel lines. It then Pushes a sticky Black Goo into the idle jet of these Carburetor's and a surge or non running issue is the result. I would replace all of the fuel lines. I eliminated my In tank fuel filter as it is not handy to change or check. I am using two fuel filter's in my fuel lines now they are both clear see through one's and lie against the Tractor's fire wall in Plain site. One is in the gas line coming directly from the gas tank and the other one is in the gas line that feed's the carburetor. With two gas filter's in Place it eliminates any further issues of getting Trash into the carburetor and they are easy to see and change. Be sure to check the Impulse line that run's to the back of your Onan fuel Pump. They can become dry rotted and when that happen's the fuel Pump will not have Proper Vacuum to operate correctly as the vacuum comes from crank case pressure when the engine is turned over or running I would replace that rubber line as well . The original Onan fuel Pump's can get Plugged up and when that happens it will cut down on the fuel delivery or make the engine starve for fuel. They can be taken apart to be cleaned. Be careful when you disassemble it to not loose the spring on the diaphragm or any other small internal Parts. Flush it well with some Gum-Out Carburetor cleaner it may have a build up of deteriorated fuel line, sediment or debris built up inside it's Port's not allowing it to pump enough fuel to your engine. I hope this helps, Kurt

 

[wmgeorge]

I'd vote for gunk in the tank. Inside the tank there is a metal mesh filter, not a really good filter but you would not believe the amount of junk that gets in that tank.
I read, and re-read your post it does not say you are using ethanol gas? Try not to use it, and standard Sta Bil works fine for non-ethanol gas, if you are not using the tractor on a regular basis.

 

[raboley]

I've only had this tractor a couple months and maybe put 2 hours on it total. Its had a rough life. I noticed someone had even disconnected one of the lines from the tank, so I can only image why! Its a "fun" tractor and not a worker, but we are taking 3 tractors to a little towns parade for the 4th. It just needs to run long enough to make it through the parade route for now!

For the fuel lines, just standard 3/16 fuel line?