Cub won't start when cold under 20 degrees

[barnE]

Fella told me that this problem was always and only due to weak magnets in magneto. This tractor starts all summer, runs like a champ. Is this likely true or possible. It already is on 12 volt and does have some smoke issues. I have two neighbors also same situation. Need heater to start at all in this weather. 20 degrees. Using heater seems too costly. Dave Thanks to all you guys and gals.
 

[David G]

Does the choke work?
 

[Royse]

I'm not quite sure what you have going on there Dave, but my Cub always starts.
Even when it was so cold the rear end would not turn and would kill the engine!
Are you saying it won't roll over, or doesn't have spark or maybe frozen water in the gas line?
I have the J4 magneto on mine, 6 volt system.
 

[Walt Davies]

Magnito doesn't use battery voltage so the volt is only good for the starter. Mags needs cleaning now and then since they work on very low primary voltage. Make there is no rust on the coils where they attach also clean the points so that they are clean and dry.
It might just pay to take it apart and thoughly clean it from to to bottom.
Walt
 

[Royse]

[teddy52food]

Maybe try using that hand choke when it is cool.
 

[donjr]

Do some shopping (Horrible Fright or Northern Foll, maybe) and try to get a MAGNETIC HEATER. It's kind of a neat gadget that has a magnet and a hot plate attached to it. It clamps on the side of the engine or on the oil pan and heats it up.
 

[gene bender]

Have the mag checked out then do the carb you sure dont need 12v to start a Cub. Ive worked on a few and they are easy to start just a 60 cu engine does it have good compression.
 

[El Toro]

Pull off a plug wire and have someone try to make an engine start. You should see a hot blue fire from the plug wire. If the fire is weak check your magnets for magnetism using a flatblade screwdriver. It should attract that screwdriver with a lot of effort. If the magnets
appear ok I would install a new coil. I would also have copper wire plug wires and make sure your impulse coupling is snapping when making a start. As been mentioned do a compression check. Hal
 

[John B.]

Sounds like everyone has covered most of the cures but make sure your spark plug wires are of solid wire type, not TVRS (carbon type) wires, they don't work on a mag!
 

[barnE]

Sorry. Blew the posting. Have what looks to be good spark, cranks fast. Just don't want to take off and run. Copper wires already. Went through mag. Had shop go through mag. Didn't know about rust however. Compression is sorta low. Thanks for some new ideas. Will keep trying. My two neighbors gave up couple years back. It is like these cubs can read the thermometer. Dave