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engine reporting


Tom Deutsch

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Sometimes -- not always -- after I've run my tractor -- D/A 917 with the Series II KT17 -- I get one "pop!"[:0] a second or two after I switch it off. My neighbors are impressed with all the work this thing can do, but this shot ringing out is an embarrassing punctuation mark to put at the end of a good tilling session. Yesterday, when it backfired as I stepped oof the tractor, I grabbed my chest like I'd been shot and for a second had my neighbor alarmed;). So is this backfiring a harmless practical joke or am I risking damage to the engine by not pursuing a fix to this condition??
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My Dad has a small John Deere with a Kohler 13hp engine that does the same thing. I've found that letting it idle a bit before shutting it down eliminated the problem. Turn the key to off while still throttled up...KA-POW! [:0] If you think it's loud outdoors, it really gets your attention inside a garden shed. One more benefit to wearing my trusty Peltor earmuffs while tractoring. They also keep those pesky gnats out of your ears. ^
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once again I'm probably wrong. But I think factory states to shut off under full throttle. And the Magnum series has an electonic fuel shut off built into carburator. Al Eden has a better description of this situtation
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I had just come down from full throttle. I'll try the idle down trick. So, it's not related to timing (points gap) or running rich?
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I believe its fuel detonation in the muffler from heat after spark has been terminated in the cylinder. Fuel is drawn in from the carb but not ignited by the sparkplug.
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Don't forget the carbon build up on the exhuast valve. This I think is the hot spot leading to a red hot ingnition source for fuel pulled into the cyl. dureing shut down. When the ign. is removed the engine still pulls fuel/air into the cyl. Since there is no ign. to fire it it passes by the red hot carbon on the exhaust valve and it follows the trail out through the muffler. =POW Idleing should help this to cool the inside of the cyl. down. Pulling the choke would put more raw fuel in the cyl. but should also richen the mix enough not to fire. The extra fuel will also help cool.
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Don't know about on the twins but on the K series singles pulling the choke out (closing it) just before it dies eliminates this problem.
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great topic heading! I wouldn't let it go too long in case it starts burning a valve(s). Plus it stresses the muffler, which is no fun removing.
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Hi, I think I addressed this situation quite a while back. If anyone can find it and copy it in here fine, if not I will address it again. Thanks Al Eden
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quote:
Originally posted by RayS
quote:
Originally posted by Simplicity314
What was that replacement head gasket made out of? Gold?
5 hours labor per simplicity rate manual and the cost of the gasket, new head bolts, oil and filter.
Dang man, a head gasket on a mower is a backyard job for me, usually less than an hour's work if there isn't many obstructions or things to get in my way. Even with the new bolts and gasket as well as the oil and filter that task can usually be brought in for less than $50.
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quote:
Originally posted by Al
Hi, I think I addressed this situation quite a while back. If anyone can find it and copy it in here fine, if not I will address it again. Thanks Al Eden
This might be it Al http://www.simpletractors.com/club2/topic.asp?ARCHIVE=true&TOPIC_ID=40982 http://www.simpletractors.com/club2/topic.asp?ARCHIVE=true&TOPIC_ID=42119
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I always shut down my briggs M-19 at idle but the question is ,it continues to rotate several times before totally stopping,does this indicate low compression ? never back fires.
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quote:
Originally posted by RayS
quote:
Originally posted by bigcountry
quote:
Originally posted by RayS
quote:
Originally posted by Simplicity314
What was that replacement head gasket made out of? Gold?
5 hours labor per simplicity rate manual and the cost of the gasket, new head bolts, oil and filter.
Dang man, a head gasket on a mower is a backyard job for me, usually less than an hour's work if there isn't many obstructions or things to get in my way. Even with the new bolts and gasket as well as the oil and filter that task can usually be brought in for less than $50.
Your not going to change the head gaskets on a vertical twin kohler command in under a hour. I more than likely could have done the work myself, I do all the maintenance on all my machines. But when you work 65 - 70 hours a week and 6- 7 days a week there isn`t much time to do anything else. I didn`t figure that it was to awfully bad when you consider the service that I get from this dealer, the knowledge and quality of work that he and his employees perform and him still surviving in a box store world.
Did they use lube?:p Also the hard working kt's do tend to have quite a bit of carbon buildup, so might be good idea to clean the heads after you pickup a tractor. just watch for the typical hole in the block on the "passenger" side just infront of the head.B) Anyone ever come across a kt-21??
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My K321 on my AC 914 used to back fire also. I reset the points, and adjucted the carb, can't remember if i leaned it or riched it but it doesn't backfire any more. So I did something right.
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Its raw unfired fuel exploding in the exhaust from the heat.You may kill the ignition but while engine is still revolving it is taking in fuel and doing its 4 cycle process.
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Of all my tractors with engines (11) only the 2 with KT17s have this backfire problem. I idle down the engine for 15 seconds or more before turning off the ignition, and no backfire.
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