Engine runs 20 seconds, then quits

   / Engine runs 20 seconds, then quits #1  

JazzDad

Gold Member
Joined
Jul 11, 2003
Messages
424
Location
In the city now.
Tractor
Main: Case 235
This has got me baffled. My JD rider has a PA540A engine in it. It starts very quickly, but then dies after 20 seconds of full throttle running. If I start it then quickly throttle back, it will run for 30 seconds. The fuel tank is not creating a vacuum, because the same symptoms apply if I leave the gas cap off. The fuel shutoff solenoid on the carb is opening, and the float is allowing fuel to flow quite well without the engine running, even through the fuel pump. All the fuel pump baffles/ bellows seem intact and flexing. Nothing seems gummed up in there.

It seems fuel starved to me. Perhaps a fuel line collapsing? I tried dripping gas into the throat of the carb at low speed. It backfired a bit, but still died at the same time (30 seconds)

I have not changed the plug. It just seems too consistent to be the plug heating up and then going bad at the same time, every time.

Replace the fuel lines first (all 5 feet of them)?
Spark plug first?
Remove & thoroughly clean the carb?

Thanks in advance.
Bret
 
   / Engine runs 20 seconds, then quits #2  
sounds like a fuel issue.. maybee stuck float needle.. had a brigs do that.
 
   / Engine runs 20 seconds, then quits #3  
"and the float is allowing fuel to flow quite well"

Wow.
 
   / Engine runs 20 seconds, then quits #5  
water in the fuel?

fresh fuel and drain the bowl.

just a thought.
 
   / Engine runs 20 seconds, then quits #6  
Check the fuel filter.

My neighbor had that exact same problem two weeks ago when he called me to look at his JD.
I changed his gas filter and it's been running like new ever since. I never saw so much sludge in a fuel filter before. Come to find out his grandson had used the gas can to drain an old fuel oil tank and never cleaned the gas can out again before refilling it with gas. :confused3:

It's a good thing that sludge did not make it to the carburetor. Short of pulling the gas tank of the GT and cleaning it out, I told my neighbor to keep another new gas filter on hand.
 
   / Engine runs 20 seconds, then quits
  • Thread Starter
#7  
Soundguy and Willl: With the carb bowl removed, the fuel flows freely with the float hanging down (open). When I push it up, the fuel flow stops.

GreenRules: I have read this around the Interwebs. I hope to get a plug today to try this.

Glgeek: It's fresh fuel. I drained what was in there from last year, even though it had stabilizer in it and didn't smell 'sweet'.

Oldoak: Fuel filter has no restriction. Fuel flows well through it.

I will report my findings.
 
   / Engine runs 20 seconds, then quits #8  
Soundguy and Willl: With the carb bowl removed, the fuel flows freely with the float hanging down (open). When I push it up, the fuel flow stops..

Yes, I read that in your first post.
 
   / Engine runs 20 seconds, then quits #9  
Bret,

one thing you didn't mention, is when you start it and it runs for 20 seconds and dies. does it do the same thing when you engage the starter again right away? or do you have to wait before it will start again?

ba
 
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   / Engine runs 20 seconds, then quits #10  
Yes, I read that in your first post.

it was a good thing to doublecheck though. can';t tell you how many tractors I've fixed for start-run-stall afte rhte owner said it had fuel flow, by checkign the flaot needle.

not always it. but never hurts to check twice. that's a common prob on some smaller engines like brigs with no pulsa pump.
 
 
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