I could use some help. I have an issue where my GX390 dies after using it 1-2 hours (it’s running a 5gpm Udor pump from a gearbox). It starts to struggle for about 30-60 seconds and then it dies.
Once it dies the first time (after being fine for a couple of hours) it won’t run but a few minutes after re-starting it.
When it first started happening a couple weeks ago, it would only run initially for 10-20 minutes.
When I started troubleshooting I saw that the ignition coil was torn so I replaced it.
It helped quite a bit and I went from getting 10-20 minutes to getting 1-2 hours.
I noticed a fuel line was loose so I used a clamp to tighten it down in case air might’ve been getting sucked in.
I took off the carburetor and cleaned it really well.
I changed the fuel filter.
Oil level is good.
I did unhook the oil sensor in case that was the problem but it wasn’t.
After all that, I’m still only getting 1-2 hours from it.
maybe your fuel tank isn’t venting and you end up with no fuel in carb bowl. when it happens again, pull the purge bolt from the carb bowl to see if it’s full or nearly empty. or something he clogging fuel line. it does happen. the little rubber bits of a worn fuel cutoff gasket goes somewhere.
Take along some starter fluid & see if a good pop will make it run for 2 seconds after it dies. If that brings it back to life for 2 seconds, you’ve isolated a fueling issue, which is the most common culprit. That engine needs 5 things to run (6 to stay alive). Give it a new spark plug, air filter & adjust the valves while you’re at it.
I know you just replaced it, but that sounds like the ignition could - again - to me. Older small engine shops might have an ignition coil checking machine. Not sure if anyone around you would have one or not. Only one of the 4 stores I worked at had one and we’d have folks coming across county lines to have their coils tested before spending what could sometimes be a ridiculously large wad of cash on a new one.
But the others are right about also checking to see if popping the fuel cap off as it’s trying to die.
I had similar issue before, i cleaned out carb and still had an issue, ended up unscrewing with needle nose pliers, the on/off fuel lever, take the plate that hold that lever, and remove any gasket in there n spray with crab cleaner, mine would run 1 to 2 hrs and after sometime of deaing lwith that it wouldn’t even run. There was crap in that canister.
So I have a gas pump that pulls from my Kohler tank. The cap on that has a vent big enough that when you hold it up it to the light, you can see the light coming through. But I’ll try unscrewing the cap when it happens again.
I guess it’s possible the little gas pump is failing? Seems odd that it would work fine for hours and then stop. But I’m going to find another one and consider swapping it out.
Oil level is good. And I disconnected the oil sensor when I started having problems in case the sensor was bad. But connected or unconnected I still have the problem.
Try swapping it & you’ll have a spare if nothing else. I had to replace a 12v fuel pump on one of my vehicles recently and it was tough to track down because it was intermittent. I’d have it towed home and it would fire right up in the driveway. In my gx390 days I kept the Everest parts kit in the toolbox and a spare gx390 in the shed. Recoil assembly alone saved me on a few jobs. Hopefully it hasn’t contracted ‘Kholer cooties’ from sharing the fuel cell.
I keep parts of a lot of things on the truck.
Interesting you mentioned the recoil assembly because the rope broke on me on the last job after I started it the second time from dying. So I had to buy new rope and rethread it.
