Dixon mower with Kawasaki FS651 engine cranks but wont keep running

Gary Fowler · Jun 7, 2015

My neighbor has a Dixon with Kawasaki engine that quit running after daughter put in some questionable gasoline that was at least 3 months old and a little brown. This I discovered when I drained it and put in fresh gasoline. I blew out the fuel filter, drained out the gas line all the way to the carb but it still starts up, runs a few seconds then dies. It needs about 1/2 choke for it to run but seems to do fine till it sputters like it runs out of fuel and dies. It has to set a couple of minutes and then it fires right back up to run 10 seconds again before it dies.

I think it has a vacuum operated fuel pump on it, at least I think that is what it is, fuel goes in one side comes out the other but it has another line coming from the bottom and routed back somewhere to the engine (I couldn't see where it was attached).

Anyone have any advise on something to check before my neighbor takes it to the shop for a going over? I know it also needs some new blades or at least sharpened but that isn't the problem with the engine.

NOTE: It was running fine and mowing till it ran out of fuel and his daughter put in the questionable gas. It immediately started sputtering and smoking and wouldn't run without full choke on it. Now if runs with 1/2 choke, doesn't smoke, doesn't sputter till it just seems to run out of fuel and dies.

bullbreaker · Jun 7, 2015

For starters and I 'am not a mechanic I would have ran Sea Foam through it and also treid to see if it runs with fuel cap off .

Gary Fowler · Jun 8, 2015

I did have the cap off, even tried it with pressurizing the tank a bit by blowing air into it but the same thing regardless. I did think about some sea Foam but I don't have any and neither did my neighbor. I am puzzled by the fact that it happened within minutes of using the 3 month old gas (according to the daughter). It ran out of gas, girl refueled and it immediately started running rough and needing the choke to keep it running. With fresh fuel, it runs perfectly when running, it just wont remain running so I believe it must be starving for fuel but I have no idea what to check next.

bullbreaker · Jun 8, 2015

Gary I'am surprised you haven't got more responses on here as to what it could be. When you fiquer it out post solution would Ya ? Be interesting to know what it was .

zzvyb6 · Jun 8, 2015

Kawasaki motor on my JD525 had same issue. Inspected the fuel pump diaphragm too, but found nothing. Key finding was that the inline fuel filter was never full and took 30 -40 seconds of cranking to start. New fuel pump from ebay and it now runs perfectly with full power. In fact, just started it up after an idle winter and it fired on the 3 rev. Not so sure about the blame for bad gas. I regularly use gas that's 6 month old with no additives or special storage conditions. (Unless there was water in it). You may have to drain the carburetor in that case.

PapaPerk · Jun 8, 2015

zzvyb6 said:
Kawasaki motor on my JD525 had same issue. Inspected the fuel pump diaphragm too, but found nothing. Key finding was that the inline fuel filter was never full and took 30 -40 seconds of cranking to start. New fuel pump from ebay and it now runs perfectly with full power. In fact, just started it up after an idle winter and it fired on the 3 rev. Not so sure about the blame for bad gas. I regularly use gas that's 6 month old with no additives or special storage conditions. (Unless there was water in it). You may have to drain the carburetor in that case.

Yeah I doubt 3 month old gas is the problem. It's fuel starvation most likely.... Not enough fuel getting to it. May need new fuel pump.

Dave M7040 · Jun 8, 2015

The most critical test is fuel delivery to the carb. not just at the filter where gravity will bring the fuel as it is lower than the top of the tank.
A pump is needed to get the fuel up to the level of the engine which is above the tank especially when the tank level is low.

The fuel pump is typically a vacuum operated pump located on the engine itself.
Here is a typical picture. Ebay for $10 to $40 depending on if it is a China made product or American

The brass small plug in the center of the pump is actually an air filter made from particles of brass bonded together so air can pass through.
This allows the pump diaphragm to move back and forth under the vacuum of the engine and deliver the fuel.

Trace the black fuel line from the carb and you should find it.
The pump will have a black line for fuel from the tank and then the output line to the carb,
Finally there will be a vacuum line going to the intake manifold on the engine.
Disconnect the fuel line at the carb and direct it into a container as someone cranks the engine.
Fuel should be coming out in pulses.
If not a new pump may be in order.
As a final step, I would try and either find a drain plug on the float bowl or remove the bowl itself as crud will stay in the bottom and be sucked up by the main jet.
If you get the bowl off, try and spray carb cleaner with a straw which comes with it into any opening or jet you can see with the bowl off

Remember you are working with a flammable liquid so dont do this inside your garage where a fire could result.
Dave M7040

Last edited by Dave M7040; Today at 11:33 AM.