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Backfire
My 6X4 on shutdown will backfire after about 1-2 seconds. It is definitely in the muffler. Is it running that rich? What would be the ignition source? The plugs look fine and it starts right up.
Thanks
JK
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Backfire
Johnkom,
My best guess would be that there's unspent fuel going into the exhaust pipe after shut-down.
The heat from the exhaust pipe, or exhaust manifold, is enough to ignite it once it reaches the proper mixture for burning.
You might give this a try.....see if it changes anything.
Immediately after shutting down the engine, hold the brake and then pop the clutch with the machine in gear. This will instantly stop the engine from free-wheeling.
If it doesn't backfire after trying this, you know that the problem was caused by the coasting engine pumping raw fuel into the exhaust system.
If it still backfires after this test........Hmmmm. I'd have to ponder on that one for a while.
Joel
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Backfire
Joel; There is no foot clutch on a Gator, they work like the old Cushmann Motor scooters. I'd try just letting it idle for a bit before cutting the spark. We have two Deere 345 lawn tractors identical in every way, one you need to let idle for a bit or KABAM, the other one never does backfire. There is no adjustment on the carburetor of the mowers. The M and Super M Farmalls were known for loud backfires if you cut the throttle while slowing down from full raod speed, kinda neat really. Frank.
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Backfire
Frank,
I've never owned a Gator. I thought about the possibility of having no clutch on the darn thing, long after posting the message.
I shoulda done checked more better before opening my....um....keyboard. hehehe.
Thanks for setting me straight, my friend.
Joel
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Backfire
Hi Johnkom.
Candoarms is right about the unspent fuel entering the muffler and causing a backfire. I have seen this condition so bad that the backfire caused the nylon teeth to sheer off the cam gear resulting in a complete camshaft replacement. The problem is usually caused by the nylon float in the carburetor rubbing on the end of the aluminum fuel inlet needle valve. The float is actually abrasive enough to wear the end of the needle valve where it contacts the float.(When you compare a new needle to the old one the difference in lenght is quite obvious.) This results in less float pressure force to hold the needle on it's seat and allows excess fuel to flow through the engine and into the exhaust system. One of your spark plugs is probably running richer than the other as well - usually the front. I spent considerable time on this problem after the first 6x4's had been in service for a few years and this situation arose. Replacing the fuel inlet needle should take care of the problem. Be sure to check your pushrods and valve clearances as well. I have seen some bent push rods due to the backfiring. Hope this helps.
Deano
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Backfire
If raw gas is getting in the muffler that can klead toa real disaster. I have a 13 HP B&S lawn tractor that would dump gas into the muffler and would spit it out until it fired up. Progressively quick the problem got worse to the point it would shoot out more gas--but it still started no problem. One day it wouldn't start. Stupidly, I knealt down next to it and jumped the starter, gas shooting out, while my helper turned the key. All of a sudden gas sprayed out like a power washer---on my hand, up my bare arm and the side of my face, ear and nose. It caught fire and so did it I. I ran around in circles screaming like a little girl trying to put it out. I lost part of my ear and some of my pride. I didn't lose any stupidity though. DOH!
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Backfire
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It caught fire and so did it I. I ran around in circles screaming like a little girl trying to put it out. I lost part of my ear and some of my pride. I didn't lose any stupidity though. DOH!
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I have real mixed feelings here: first I am glad you surffered no worse.
Second it was funny to think on. Did you looking like the famous ole indian "Little Screaming Girl"? (Hey I would have not have stood still for that either.)
Third, you and your circles. Were these real circles or almost ciricles?
Fourth, surley you kid us on the level of stupidness. 
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Backfire
Speak up--- I lost part of my ear.
And don't call me Shirley or surley or even surely.
Yes they were real circles. Daaaang I knew when I wrote that eagle-eye Kenny would jump on that one!
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Backfire
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And don't call me Shirley or surley or even surely.
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I would have said "surly" would have been the right word.
Best of luck.
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I would have said "surly" would have been the right word.Best of luck.
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As hard as I was laughing and my keyboard shaking, I did good to even type as thoughts of "smoking bull" running in circles.
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Gas Generator Weather Protecti
02-01-2009, 10:33 
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