My neighbor's 424 died, and had no spark. He replaced the coil, with no success. I changed the points and condenser, still no luck. We bypassed the coil resistor, and its running fine. 12 volt system, 12 volt coil, what is the purpose of the resistor, and can we eliminate it? Coil didn't heat up, with the resistor bypassed. Ed
Member of Chapter 18, and National club
Joined: Thu Aug 31, 2006 7:00 pm
Location: Ma. Rehoboth
Zip Code: 02769
Tractors Owned: 5 "F" cubs 5 lo-boys 1 154 1 184 1 IH444 1 Oliver OC3 crawler 1 AC D10 1 IH 100 manure spreader 1 IH model B corn grinder 3 power units
by John *.?-!.* cub owner » Fri Apr 20, 2012 4:32 pm
Make sure the coil says 12 volts, internal resister. Many say 12 volts external resister. The ones that say external resister will run without it fr quite a while but will fail much sooner than with it.
If you are not part of the solution, you are part of the problem!!!
John *.?-!.* cub owner
Team Cub Guide
Joined: Sun Feb 02, 2003 2:09 pm
Location: Mo, Potosi
Zip Code: 63664
Tractors Owned: 47, 48, 49 cub plus Wagner loader & other attachments. 41 Farmall H.
I have always had the understanding that a resistor, whether internal or external, is necessary between coil and points to prevent points from burning. Start on full voltage and run on a lesser voltage.
We make a living by what we get, but we make a life by what we give......Winston Churchill
Joined: Tue Jul 18, 2006 9:55 pm
Location: TN, Lebanon
Zip Code: 37087
Tractors Owned: 1947 Cub S/N 9216 w/ C-22 Mower
1974 Cub S/N 244814 w/59 Woods Mower
Ford 3000 Gas S/N C375091 w/Bushhog QT2345 Loader & 6' Squealer Bushhog
to add to what John said, a resister is needed in the circuit - either internally in the coil, or externally in the form of the big white resister. Automobiles in the 60's (12 volt) used a start circuit that connected 12 volts to the coil for starting, then went to the resister setup when you released the key to the run position. on Chrysler and IH vehicles that was done with the resister. on GM products, it was done with a resister wire to the coil. Fords i dont recall but i'm thinking resister. if you burned out a resister, the engine would start and then die as you released the key. running for an extensive period of time with the resister bypassed will result in burnt points and coil overheating.
a 6 volt coil is just fine on 12 volts with the resister in place.