1975 JD 6oo...Piston Port 440 backfiring
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hgilbertson82
- Posts: 1
- Joined: Tue Jan 27, 2015 7:04 pm
- Real Name: Hans
- Location: Trempealeau, WI
1975 JD 6oo...Piston Port 440 backfiring
I recently picked up a KEC piston port 440 out of an older JD 500. Has an aftermarket Mikuni carb on it and upon trying to get it to run, backfires out the carb pretty steady once in the yard and riding around. Carb currently has a 300 main jet after swapping it in for the 280 that was in it. Seems like its leaning out. Park the sled in the driveway, will idle like a champ. Touch the throttle and it dies. Try to restart, nearly impossible. Once it cools off, full choke, starts on one pull.
Re: 1975 JD 6oo...Piston Port 440 backfiring
Always start with new crank seals on an engine with unkown history.
Todd Schrupp
Milbank SD
Milbank SD
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400brian
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Re: 1975 JD 6oo...Piston Port 440 backfiring
My guess is that you are way too rich. 220, 230 more like it, your mileage may differ.
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Cabindweller
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- Real Name: Jerry Zebro
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Re: 1975 JD 6oo...Piston Port 440 backfiring
I agree, Check replace Crank Seals First, Could be a bad coil or condenser too. Had a bad coil on my 74 600. It would foul that plug and had an occasional back fire. Just pressure tested the motor this fall so the seals are good, that being said I changed the PTO side seal just because.
Jerry
Jerry
Old sleds are hours of entertainment.... then you get to ride them for a little bit.