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Old 05-24-2013, 07:49 AM
williams lcm williams lcm is offline
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Location: orlando fl
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27 kaw 31kaw and 37 kaw

I had a 27 and a 31 hp kaw and I could turn them both off asap and no backfiring. I now have a 37dfi kaw and have to idle 1min so it won't backfire. Why is it doing that on the 37 and not the other motors.
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Old 05-24-2013, 11:35 AM
Vecchio Lawn Care's Avatar
Vecchio Lawn Care Vecchio Lawn Care is offline
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Location: Bel Air, MD
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27 kaw 31kaw and 37 kaw

It does that with my 25kawi on JD 757
19 Years Old

John Deere
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Old 05-24-2013, 12:04 PM
Ridin' Green Ridin' Green is offline
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Location: Michigan
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The carbed versions are supposed to be shut off at somewhere above half to three quarter throttle because they have a fuel shut off solenoid. The DFI doesn't have that feature due to its design. When you turn the key off, the spark stops going to the cylinders, but the fuel still gets pumped in for a few more cycles of the engine as it's winding down, and when the mix gets pumped on out through the exhaust valve and hits the hot muffler, you get that loud bang. When shutting off at idle there's no where near as much gas in the mix as there is at higher rpm's and thus less or no backfiring (may not be exact, but it's close to what is happening without typing half a page LOL).

My FX850 has never backfired on me (yet anyway) but I idle it for 30 seconds to a minute before shutting it off.

Last edited by Ridin' Green; 05-24-2013 at 12:08 PM.
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