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I have a Kohler KT735 (7000 series) on my new (less than fifty hours) Cub Cadet that backfires sometimes when I push the throttle lever down when I am going to shut it down. It does not backfire at any other time, so I doubt (but not sure), that the cause is not one of those listed in the Kohler engine manual (improper fuel, Dirt in fuel line, Engine overloaded, etc.), I checked the air filter, and it is not clogged. I suspect carb set too lean, but want input before dorking with the carb willy-nilly...besides, I don't know where the carb is on the Kohler engine, nor what to turn to adjust.

Kohler recommends that their engines be shut off at full throttle. It has to do with the fact on the Kohler engines the fuel shutoff solenoid only blocks the high speed jet but still allows the low speed jet to draw fuel. That fuel is being passed through the engine since there is no spark and then is ignited in the hot muffler.

Just as a possibility.
If the exhaust had a leak and you shut the engine off, the engine can suck in colder air to make the muffler 'pop".

Richie F said:

Just as a possibility.
If the exhaust had a leak and you shut the engine off, the engine can suck in colder air to make the muffler 'pop".

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The backfire is not a "pop" it is a "bang" as loud as a .22 Long Rifle pistol in a confined space (my garage).

ILENGINE said:

Kohler recommends that their engines be shut off at full throttle. It has to do with the fact on the Kohler engines the fuel shutoff solenoid only blocks the high speed jet but still allows the low speed jet to draw fuel. That fuel is being passed through the engine since there is no spark and then is ignited in the hot muffler.

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Where can I verify that "Kohler recommends that their engines be shut off at full throttle."? I did not see that in the owner's manual.

So it's not backfiring when you turn the key off, but when you idle it down?
my Cub has a Courage 19, and i would always idle it down and turn it off, but it would still backfire (even with the afterfire solenoid on the carb) Now what i do is let the engine idle for about 1 minute, or the time it takes me to blow the mower deck off with the blower. pull it in the shed at idle, and no backfire.

dahermit said:

Where can I verify that "Kohler recommends that their engines be shut off at full throttle."? I did not see that in the owner's manual.

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Page 4 of the owners manual under stopping.

Stopping
1.If possible, remove load by disengaging all PTO driven attachments
.2. Position throttle control between half and full throttle; stop engine
.3. Do not allow engine/application to be left unattended with key ON (RUN position) for long periods. If left in such a condition, operator must turn key completely OFF before attempting a restart to reset system.

ILENGINE said:

Page 4 of the owners manual under stopping.

Stopping
1.If possible, remove load by disengaging all PTO driven attachments
.2. Position throttle control between half and full throttle; stop engine
.3. Do not allow engine/application to be left unattended with key ON (RUN position) for long periods. If left in such a condition, operator must turn key completely OFF before attempting a restart to reset system.

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Thank you. I will adjust my shut-down procedure accordingly.