Hello guys, my first ever post here. I have a gx690 and after getting good and hot the machine turns off. We would wait and it would cool down and wash for another 10 min or so. It’s been a real pain to get things done. We have glass fuel filters and decided to observe the machine for a while. Started to notice some air bubbles in the glass filter and were puzzled. Checked spark with testers and all looks good. Started reading all over and came across idea that gas is evaporating in lines. Hence maybe why we saw air traveling backwards to fuel filter? Has anyone had this happen and more importantly how did they fix it? New carb or fuel pump?
Try this first: when you notice the machine beginning to stutter just loosen the gas cap on the fuel tank and see if it comes back to life. Some of these machines have been known to have an issue with the fuel cap not venting properly.
It just cuts out too quickly, no stuttering. Cap is vented. Cap on, cap off makes no difference. Whatever is happening is happening AFTER fuel filter closer to carb
I don’t know much about GX690’s but don’t they have a fuel pump that pulls in gas? Maybe a loose clamp on a fuel line or something could be allowing it to suck in air? If you can get it to run off starter fluid when it won’t run otherwise, you’ve at least isolated the problem to be a fuel issue.
Could be a fuel pump issue then but start with the easy stuff like Wizard mentioned. Make sure lines aren’t collapsing and no kinks anywhere then go from there. Haven’t had any fuel delivery issues with my 690 but plenty with the Vanguards. Could sometimes tap on the fuel pump housing with the handle of a screwdriver and get it to keep going.
It runs for about 30 minutes at full power and then decides to cut out without any other variables. Time passes by to cool and runs again with no adjustments made.
Today was rainy, cloudy and cool and it started back up within 3 min after it initially cut out. The other day it took like 15 on a much much warmer day
An engine need 5 things to run (6 to stay running). Over half the time there is a problem, it’s a fuel delivery issue. Cars, lawnmowers, leaf blowers, etc… If you’re going to run it on a job: next time it quits, take along some starter fluid & shoot it in where the air filter goes to see if it runs for 5 seconds & dies if you want to be sure. If it does, that rules out compression, timing, spark, etc… Based on your description, it sounds like it’s sucking air somewhere between where you’re seeing air bubbles & your fuel tank. Maybe a loose clamp or loose filter, who knows but if it will run on starter fluid when it won’t run on anything else you’ve got a fuel issue. I’ll trade you a good running GX390 for it tomorrow if you’re willing to do the driving. 
Overheating is also a possibility. It’s worth mentioning, these air cooled engines need to be run at or near full throttle to cool properly. Also, timing that is too far advanced can cause overheating but that shouldn’t be the issue if it has just started happening out of the blue. That being said, make sure your oil level is good & take some starter fluid along next time you run it just to see what happens. Just my 2 cents.
y, I was going to suggest, check your oil level. they’ll cut off in a sec if oil level low. Then maybe it drains back down and sensor doesn’t cut if off for awhile.
The other solution is just work faster, lol. 30min house washes. Good luck with it.
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Ignition coil - is my guess.
First thing k would have done is check the fuel cap for vapor locking.
Second, check that fuel filter is facing correct direction.
Third, get an ignition tester to see if a coil is going out.
Engine starts and runs fine then it will usually cut off just as if someone reached over and killed the ignition switch (single cylinder engines). Two. Cylinder engines start to run real rough. Either way, if you can only restart engine after letting it cool down for a bit then this is likely your issue.
If you’d do get a spark tester you’d have to test it immediately after the engine shuts off, otherwise it’ll cool down to the point of it becoming operational again.
Oh, and check your engine oil level and ensure it’s on level-ish ground.
What fuel tank do you have? How many hours are on the machine? Do you habe any pictures
I like the ignition coil for this. To test it while it’s running mist some water into the blower housing and it will knock out that coil if it’s already failing
Air bubbles are in the glass fuel filter. I’ll try the starter fuel test. Just to be sure
Coil testers on both plugs…they are firing just fine right after it cuts out and I try starting it the tester shows spark. Tells me it’s a fuel issue
Nice looking rig sir! If it were mine, I’d slap a new spark plug in it just for the heck of it & adjust the valves to stay ahead of the curve on maintenance. Sometimes little things go a long way. If you have a leak down test kit handy, may as well give that a stab while you’re at it to make sure you’re not loosing compression through the intake valve. I had problems last spring with a brand new engine & I was a nervous wreck on every job. This year I have a great running engine & a spare in the garage. The peace of mind that comes with backup equipment is well worth the investment.
Thank you very much. Brand new plugs. I don’t know anything about valves or how to adjust them.
I’ll look that up
Shawn Planas
Sales and Service
(407)777-6388
www.soakedandco.com
Soak down, Clean up
| TheWizard
March 25 |
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Nice looking rig sir! If it were mine, I’d slap a new spark plug in it just for the heck of it & adjust the valves to stay ahead of the curve on maintenance. Sometimes little things go a long way. If you have a leak down test kit handy, may as well give that a stab while you’re at it to make sure you’re not loosing compression through the intake valve. I had problems last spring with a brand new engine & I was a nervous wreck on every job. This year I have a great running engine & a spare in the garage. The peace of mind that comes with backup equipment is well worth the investment.
Show me a pic of the back of truck, want to see how you have that SC mounted.
Update: so i contacted Diego with MVP services on the advice of William. He told me like others here to go back to basics. I had the carb cleaned about 2 weeks ago by a local lawn mower repair guy. Simple guy. Did a good job. Or so i thought. Basically he didn’t tighten the bolts securing the carb which means no seal. The only way i found out was my checking out fuel lines to make sure they were not pinched. As the engine was running i saw the bolts shaking freely🤨
I tightening the up and seems to be running without any hiccups.
All the advice really helped to narrow it all down that you guys.
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I’ll take a pic once it’s all back together
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