Farmall Cub

my tractor ran great all summer but now its cold once again she fights me every time i try to start it. it will fire, die; fire then die, fire then die maybe if you are lucky it might stay running. i love these tractors in warm weather but they suck once it gets cold. i just dont think updraft carburators are a good thing in cold weather. i had a snowblower that had an briggs with an updraft carb and it was the same way. will this thing ever start easy in the winter i have my doubts. it has good plugs, wires, points, ect. the best winter starting engine in my opinion, kohler cast iron kseries. the cub i love my tractor but hate in the winter. shouldnt it run the same in the winter as it does in the summer. this tractor is nothing but a pain in the rear once the weather gets cold. i also hate guessing i dont want to go and replace hundreds of dollars of parts to MAYBE get it to start better in the winter. warm weather starting is effortless often time choke isnt even required.

also where do i a get good 6V battery because my battery is shot. been trying to hand start what about an 8 volt battery might spin it over faster make starting easier. this tracto really is a pain in the winter, i understand now why they dont build them like this anymore. .well built but very temperamental in cold weather. it ran so good this summer i even forgot about what i pain it is in cold weather.

I guess i'll differ with you on the kohler cast iron series. there is no compression release, making them hard to spin in the cold....

but on to your cub. a poor 6 volt battery will not give the spark needed in the cold, assuming it has battery ignition. the battery de-rates as the temp goes down. the old farmers tell me about bringing the battery in next to the stove at night - a good battery, that is.

if you want it to start in the cold, convert it to 12V, add an alternator and electronic ignition. now you have a chance....or buy a new 6 volt battery and keep it next to the stove.

I know the CP will be on this...

k series dont have compression release. sorry your information is incorrect. have you ever rebuilt a k series? you could have had a k series with a failed compression release but i have never seen that happen. on a k series camshaft there is a tab mounted on the exhaust lobe of the cam. as the cam is spinning at cranking speeds the tab extends holding the exhaust valve open for starting. once the engine is up to RPM the weights mounted on the camshaft gear retract the tab and engine will run at full compression and power. they do, in fact have compression release. does the C60?

as far as converting to 12v i dont want spend hundreds buying an altenator, replacing the starter, and all lighting (i do run the tractor at night) also battery voltage has no effect on how hot my spark is, as i have a J4 magnetor not battery ignition. if i ever did go the 12v route, i would retain the mag.

what is the cost on 12 v conversions?

did they make 12v generators instead of hacking a 12v delco altenator on the tractor and messing up a good hood. i need a battery anyways so perhaps i should do a 12v conversion. what is the easiest way to go about it? can i keep the tractor postive ground and replace the 6v gen with a 12v gen and the starter with a 12v starter?

Yes they made 12 volt generators, they also put delco alternators on them from the factory! And the hood was not hacked up!

I prefer 6v and all my runners start up on the coldest day, but that is just my preference. It sounds like you have convinced yourself to go 12v. If so, then get a Delco one wire alternator. You don't have to hack the hood. Probably less than $200.00 for the switch over. I believe there is a how to in the "How To" forum on this.

If you decide to stay with six volts then a good battery is about $90.00. Buy a maintainer for under $20.00 and you won't have to keep it by the stove at night. Regardless of what you decide, don't get an 8V battery.

And you don't necessarily have to change the starter to 12V.

I changed my 48 mag. Cub over to 12V for the cost of a Walmart battery and three bulbs. Haven't had to charge the batt.. That was 4 years ago. The voltage reg. is pretty loosie goosie so I guess I get enough voltage spikes to keep it charged. My cubs start easy. They have to or no one could have hand cranked them.

they start easy?? so what gives with mine because its really irritating. i can start it in the warm weather by hand but in the winter forget it. for a while when my battery went south i did in fact hand start it, it was fairly easy. winter is another story.

ad356 wrote:they start easy?? so what gives with mine because its really irritating. i can start it in the warm weather by hand but in the winter forget it. for a while when my battery went south i did in fact hand start it, it was fairly easy. winter is another story.

Many variables there, when was the last complete tune up? Was it done by someone that knew what they were doing? Has the carburetor been overhauled? The cub is 1940s technology, it does not have an automatic choke , nor is it fuel injected.
It can be many things causing it not to start when cold. Low voltage would be my guess but is only a guess, bad plugs, bad wires, the list is endless. Bottom line all things being equal it should crank as well when cold as warm.

ad356 wrote:i have a J4 magneto not battery ignition.

Does magneto's impulse coupling click when hand cranking the engine in cold weather?

Got spark to spark plugs?

If the battery has enough umph to turn over the engine when cold - that's not the major problem.

Suggest complete engine tune up, including compression tests, and valve tappet adjustments. Check gaskets, block to manifold, manifold to carburetor. Assuming compression is good. The cold start problem is either ignition/magneto or carburetion related.

My 6v Cub is no more difficult to start in cold weather and for the last 5 or 6 years has been sitting under a shed, almost like being outside.

Back when I was a "real farmer" and by that I mean all my family's income was generated by the farm operation, the implications of an engine not starting was huge. We had many nights below zero degrees and it started at 5 a.m. with getting feed, manure removal, snow removal etc. If a tractor was in an unheated space, I had 110 volt battery warmers which were a plate about 5'16 inch thick, under the battery. A warm battery is exponentially more powerful than a cold one. Together with an engine warmer, the chances of an engine not starting were slim. Never used the "tenders" but I'm sure they're good too.

All of the above suggestions! Would bet all 5 of mine would start (2 of them w/o choking), have never removed battery in winter, do start them periodically, sta-bil in gas, going to be 9 deg. in the AM, w/check them out!! Knock on wood! LOL ! Dusty B

Myself, I agree with Barnyard. All my tractors with the exception of garden tractors are 6 volt and start and run well in any weather. On really cold days it may take an additional 2 seconds to fire up an I need to run them on choke for a few minutes but after that, all is good. If you have good spark my guess is you have a lean condition in the carburetor. I suggest removing the main jet (brass hex on the side of the carb) and make sure it has no partial blockage. If all is good there, maybe turn the idle screw out a 1/4 or 1/2 turn to richen the mixture a bit for the colder weather.

Oh yeah, I strongly recommend a battery maintainer....