The 300u cold start project at 16 degrees...

Dave H (MI)

Well-known Member
....failed today. Full choke, cranked right over and fired. One maybe two seconds and it stopped. Never fired again. Seemed to crank slow. Even with a whiff of starter fluid there was no fire. So she was good at 30 degrees but sluggish and as described at 16 degrees.
 
My guess is spark voltage at the coil when cranking. Use a separate battery on the ignition (disconnect the ignition at the coil to allow the different battery to supply to only ignition volts) If it starts, the voltage to the coil needs to be provided at a higher level. Describe your battery cables, coil and resistor if any. Jim
 
I agree with Jim good chance the starter is taking to many amps for the system so your spark is weak. I would check your spark as your spinning it over and make sure it is a good blue/white and jumps a 1/4 inch gap or more at the coil wire and at the 4 plug wires. I know I have started to 300U we have in cold weather with no problems but it is also a 12 volt set up
 
I'm unclear what you are telling me to do with the battery. As for description, this is a 12 volt system, all new cables, new battery in Spring 2016, replaced starter solenoid and battery cutoff switch at same time. No resistor, 12v coil is original.

It started the one time cold but after that the cranking was much slower and Im thinking if there was good spark the fluid would have at least made a pop. Starter was tested last Spring at a shop also.
 
The slow cranking is due to reduced voltage at the starter motor. If the volts at the starter (measured while cranking) is less than about 10 volts, it will be slow.
The tractor was 6v pos ground when new, so the coil must have been changed. If the coil is marked 12v, no external resistor required, it is happiest with 14.2 volts. Less then 10 will make weak spark.
My suggestion above is to hook a different 12v battery directly to the coil input (this requires removal of the wire from the key so the different battery is not feeding energy into the wiring to the key, just to the coil and ignition. This provides nice 12v to the ignition system and isolates the tractor battery to just turn the engine. A 12v lawn mower battery will work.
If the battery voltage lowers when fully charged, it is marginal or bad. If the cables are #2 or 1-0 gauge they are OK. id #4 or typical auto size, they are too small to carry the needed current.
If the tractor starts easily with the second battery, more juice is needed. Jim
 
Don't think you can have a original 12 volt coil. If using the same coil that was before 12 volts without a resister it could overheat. Find trouble with some starter switches mounted to starter. After cranking feel the posts on both sides for heat or watch for sparks when cranking. Using a later starter switch with two small posts and wire from other post to a 6 volt coil on coil side of resister helps when cranking speeds are slow. Same system IH used when going to 12 volts on a 350.
 
There's also a good chance that you flooded it by setting the choke and leaving it. You need to "feather" the choke using the least amount of choke possible to keep the engine running, or else you will quickly flood the engine and it will not start again for hours.

Starter fluid didn't help because it already had too much fuel in the cylinders.

I know on most of our 4-cylinder Farmalls, you get one chance in real cold weather. If you don't catch it and keep it running when it first fires, you're sunk. It requires skill with the choke.
 
In cold weather you will get better starting with the 6 volt coil with the resister. That is because the resistor is bypassed when cranking and the full 12 volts, or what ever is there when you're cranking, is going to the 6 volt coil giving you a hotter spark.
 
Just because parts and battery where new in 2016 does no mean there good now. Shoot I have picked up more then one battery brand new that was not worth the time of going and getting it as in was bad from the get go. I would try a different battery and or jump it with your car of truck
 
(quoted from post at 09:29:49 12/13/17) I'm unclear what you are telling me to do with the battery. As for description, this is a 12 volt system, all new cables, new battery in Spring 2016, replaced starter solenoid and battery cutoff switch at same time. No resistor, 12v coil is original.

It started the one time cold but after that the cranking was much slower and Im thinking if there was good spark the fluid would have at least made a pop. Starter was tested last Spring at a shop also.
I see you mention a “battery cut off switch” so that is a battery disconnect in one of the battery cables? This is what I would definitely give the “warm/hot feel test” after cranking. Just a very suspect spot to lose starting amps. There are some good quality disconnects but many just don’t carry the amps like they should. Also, Mr. Slater is a very knowledgeable fellow, but not everyone speaks his language so I want to clarify one of his comments. He refers to a “two post starter switch” but what he means to say is “solenoid switch”. This allows you to have what I call an “ignition starting voltage kick up circuit.” This would be like Mr. Slater describes as found on a factory 12v 350 as well as many other coil type ignition systems until electronic ignition became the norm. Jim’s auxiliary battery test will help you determine if pursuing the addition of the “kick up” circuit is feasible. Also, would like to add that excessive choke after the engine fired most likely fouled your spark plugs hindering an immediate restart.
 
Sorry, to be long winded but I apologize if you are viewing my post in “Classic View” I just recently determined that something between the two views on this forum can’t translate punctuation properly from an iPhone. Switch to “Modern View” to see less garble. If I have time I will look back at your other posts I can’t remember what you have done with the starter. I’ll just go ahead and say it. A Delco starter like your tractor is equipped with is fairly simple inside. Even though you had it tested as good or if it was a bought as a “rebuilt” unit 6 months ago here is what I would recommend. Pull it off and loosen the back two bolts that hold the back bearing plate on. If you have a vise big enough to clamp the nose facing down in it this is the best position, if not place the nose in a coffee can. Not that it will fly apart in a bunch of pieces if not held this way, just best for a novice. Put a mark or piece of tape on the outside of the case near one of the bolts you are loosening for reference when reassembling later. Pull the bearing plate off and you will see the two bolts are long otherwise nothing connects to that end plate. Be careful there may be a washer on the shaft by the bushing.This will basically be as far as I will have you disassemble the starter. Now you need to look at the 4 brushes where they are contacting the armature do they all have at least a 1/16” of material left before any of the holders hit the armature? New is like 1/4 to 3/8”. If all looks good the main purpose of the disassembly is to make sure that all the brush retainer screws are tight, this is something I have found to be a problem in many “rebuilt” starters. Most often the screws have Phillips heads and you will be working at an angle to tighten the screws, just do the best you can. After that place a small dab of grease (half pencil eraser size) in the bushing and reassemble. If you did this and all looked good we can assume the starter is not part of your problem. Also should have said if you smell a very strong burnt smell after pulling the end plate you should probably have a pro look at your starter. Hope this helps.
 
That is like putting a band aid on a bullet wound. Take it all apart & check the armature with a growler & turn the commutator, replace & fit new bushings and put in new brushes making sure the springs have good tension. If you can't do it yourself, find some body that can.
 
(quoted from post at 10:33:39 12/14/17) That is like putting a band aid on a bullet wound. Take it all apart & check the armature with a growler & turn the commutator, replace & fit new bushings and put in new brushes making sure the springs have good tension. If you can't do it yourself, find some body that can.

Band-aid or stitches I don’t care. I’m just trying to coach him through something he can easily handle. More so trying to help him understand the inside of a starter like this is not weeping vo-do! And also want him to not trust a rebuilt/new starter as being top notch. I agree with your sentiment and as it is to me and also seems the same for you that rebuilding such a starter is easy as falling off a log. Some folks just don’t like to stand back and throw money at a problem,(whether it is the right thing to do or not) but rather take a “baby step” approach. All in good fun as long as we can help the guy along to his end goal.
 
(quoted from post at 11:36:09 12/13/17) In cold weather you will get better starting with the 6 volt coil with the resister. That is because the resistor is bypassed when cranking and the full 12 volts, or what ever is there when you're cranking, is going to the 6 volt coil giving you a hotter spark.

Not on a 300 Utility with the factory wiring. You have to get a solenoid with the extra "I" terminal on it, and wire that up yourself.
 
Thanks for all the help and apologies for not getting back sooner. I have yet another bad cold so not staying on top of stuff. A lot of snow here and frigid. Can't even get back there to look at it right now but printing off the responses and will look at it again when I am well. thanks again!
 
Used red mn. Thanks for the clarification. Maybe I was told wrong. My grandfather would correct me and say a solenoid operates a linkage to also engage starter and a switch that just makes the circuit is a starter switch. Guilty myself of calling them a solenoid. But wondering if that's correct now. Maybe the more expert electric posters can clue me in to the correct terms. Switch I was referring two has the battery cable a strap to starter terminal and one or two smaller posts sometimes marked S and I. As someone posted the 300 tractors only came with one small post, but if ever changed a big percent also have the I post now if used or not. Thanks
 

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