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Subject: Tractor won’t start

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Gary in GA    Posted 04-20-2020 at 10:12:42 [URL] [DELETE]        [Reply] [Email]  
  • Tractor won’t start
  • Went to start Herschel from his winter nap. Always just open gas pet com, turn on ignition, open the choke the width of my index finger and “varoom” starts. Not this time. Cranked and no start. Saw gas dripping from carburetor bowl and hose connector between carb and air tube. Opened the bolt under the carb bowl and drained gas out. Checked the coil and a short had developed overwinter across the primary coil. The battery was old so I replaced it also. Cranked again and I have spark at the plug. Tried starting with fuel turned off and it cranked and one cylinder fired and smoke came out of the exhaust pipe.
    It’s obviously flooded. So, do I just remove all plug and let the gas evaporate before trying again or is there some ritual for starting a flooded 8N? It’s a 12v conversion btw.

    Tim Daley(MI)    Posted 04-21-2020 at 06:58:27 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Tractor won’t start
  • Did you have the battery tested or have it on a float charger all winter? Should've had it bench tested before buying a new one. You said, "... Saw gas dripping from carburetor bowl and hose connector between carb and air tube." Fuel should enter the glass Sediment Bulb when valve is open. If you are using a plastic fuel line, that is a no-no and not recommended. How does a short just 'develop over winter'. Is it a front mount or side mount distributor? Like Bruce said, you fouled the plugs so remove, burn off with torch or one of those hand-held candle/charcoal grill igniters, gently wire brush carbon off, recheck plug gap (.027" +/- .001") and try again per Bruce's starting instructions. Firing order is 1,2,4,3 regardless if front mount or side mount. Once you get tractor running again, think about replacing that fuel line and verifying the wiring setup.

    Tim Daley(MI)

    Gary in GA    Posted 04-21-2020 at 18:35:44 [URL] [DELETE]        [Reply] [Email]  
  • Re: Tractor won’t start
  • Re: checking the battery - I placed it on the battery charger a week ago to full charge. This weekend it cranked, but poorly. My battery charger showed 59% charge on a 6 year old battery. Time to change.

    Re: gas issue - the pet cock, gas line and sediment bowl are OEM (1950), I'm second owner. I removed the drain bolt from the bottom of the bowl and emptied the gas out. I determined, subsequent to it finally starting the the carburetor has a stuck/dirty needle valve/seat as it runs excessively rich and floods the engine on all but the tiniest of openings of the pet cock. Idle screw is either flood or run rough, no in between. Carburetor rebuild kit is on order.

    Re: How does a short develop over winter? Damn good question!!! Side mount distributor. No crack in the cap, rotor and contacts have no buildup on them, points in good shape. When I measured the coil with my meter, there was a dead short between the + and - terminals. Continuity between the - and center plug wire. No spark at the spark plug. Ran perfectly last fall when I tucked Herschel in for the winter! All wiring and harness in fine shape.

    Installed new plugs (NGK as Advance Auto Parts had no cross reference for the Autolite and NGK was the only cross reference for the Champion; salesman said the NGK was the same temperature range as the Champion). Ran a jumper cable from my truck to the new battery and cranked for a long time with the gas turned off for the flooded cylinders to clear. After a lot of sputtering it coughed to life and ran VERY rough. Burning gas

    Bruce    Posted 04-20-2020 at 10:22:12 [URL] [DELETE]        [Reply] [Email]  
  • Re: Tractor won’t start
  • First, replace the plugs. You flooded it, they're fouled & it will be it next to impossible to start. You don't need to toss them; heat the tips for a few seconds w/ a propane torch to burn off the invisible spark-robbing deposits from today's additive filled gasoline........or wash them in brake cleaner.


    Gas dripping out of the carb on start up is usually operator error.


    While each N has its own starting sequence, none of them will start well by just yanking out the choke rod & holding it out for 5 or 10 seconds while the engine cranks. This is a gravity fuel system on a low compression engine; it is easily flooded by too much choke.

    Try this:

    Key on, gas on 2 full turns, clutch in, 3/4 throttle, press the starter button. Let it crank for at least 3 - 4 seconds before you pull the choke rod. Then, don't hold it out for more than 2 or 3 seconds.

    If you find out it will not start w/o excessive choking, you have problems.


    Gary in GA    Posted 04-20-2020 at 20:42:47 [URL] [DELETE]        [Reply] [Email]  
  • Re: Tractor won’t start
  • Thanks Bruce. Changed the plugs and the tractor barely finally started. When it did, it ran really rough and extremely rich. I diagnose the problem as trash in the valve and seat assembly. While running,turning the pet-cock to nearly closed and adjusting the idle down it will run almost ok. Looks like time to rebuild the carb.

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