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Backfiring

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tracker159 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tracker159 Quote  Post ReplyReply Direct Link To This Post Topic: Backfiring
    Posted: 20 Sep. 2012 at 1:51am
Ok im at a loss.Ive been troubleshooting my L134 for backfiring when i take off and under accelaration.If im setting with the jeep in nuetral it will not backfire.I thought it was the solex carb. So i rebuilt my carter and the problem still exist.Ive replaced the fuel filter and changed gas to non ethanol.All parts are new and the timing is good.Im at the end of a five year build and ready to enjoy my hard work. Thanks Confused
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garage gnome View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote garage gnome Quote  Post ReplyReply Direct Link To This Post Posted: 20 Sep. 2012 at 2:00am
Did you orient the cam and crank gears correctly? Usually back fire is too much fuel going out the exhaust and igniting or a timing issue. Firing order correct?Plugs good? Good spark? Color of the plugs? Only things I can think of.

Edited by garage gnome - 20 Sep. 2012 at 2:01am
Nate
1953 3A, 1949 3A, 1947 2A, 1918 IHC Titan 10-20, 1905 IHC Famous, other hit n misses
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Lee MN View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Lee MN Quote  Post ReplyReply Direct Link To This Post Posted: 20 Sep. 2012 at 2:21am
I would replace the condenser, My M-715 had the same problem last year, would Idle fine but on acceleration it would pop and backfire. I replaced the points and cond. and it wouldent even run as the brand new cond was also junk, took one out of a 2A engine and installed it and it ran like a top. Seems the aftermarket Chineese parts are crap. I have had good luck with the standard Ignition parts from Car Qwest, FWIW

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tracker159 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tracker159 Quote  Post ReplyReply Direct Link To This Post Posted: 20 Sep. 2012 at 2:43am
Thanks for the ideas. Ill try the points and condenser first the the timing gears.I did have to change the front plate after engine rebuild due to it being wrong.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Clone421 Quote  Post ReplyReply Direct Link To This Post Posted: 20 Sep. 2012 at 4:12pm
I had a similar problem last week. The engine would apear to idle fine, but when I drove the jeep around in 1st gear there would be a backfire every 2 minutes. Shifting up into 2nd gear the jeep lost a tremendous amount of horsepower under light load and just quit right there on the road. The engine was recently rebuilt (correctly) last fall with less then 2 miles on it. The problems went away when I adjusted the distributor timing to where the engine would start right up after half a second on the starter button.

Edited by Clone421 - 20 Sep. 2012 at 4:13pm
Kyle
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rocketeer Quote  Post ReplyReply Direct Link To This Post Posted: 20 Sep. 2012 at 11:17pm
If a new condensor doesn't cure it try another ignition coil. Weak coils will act the same way.

Larry
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JeepRoger Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep. 2012 at 1:24pm
Tracker - might want to check that spark plug leads snap on to electrodes on top of plugs. If loose, plugs might fire at idle but not under load (causing unburnt fuel to to out exhaust and cause backfire). ...R
Roger in California
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tracker159 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tracker159 Quote  Post ReplyReply Direct Link To This Post Posted: 29 Sep. 2012 at 2:46am
Thank you all for all the input.I replaced points condinser and coil but the problem still existed.I spent 9 hours yesterday on it and finally i woke up and realized that i had set up the firing order in the clocwise direction. It was firing on one and four allowing it to run but no power.Changed two and three to the correct position and now it sounds and runs great. At least now all parts are new and american made.I also now know how to set the timing realy good. Now we ride.
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