300U cold starting project...now this is...

Dave H (MI)

Well-known Member
...interesting, frustrating...you name it. I was out there looking at it yesterday to get an idea on what was needed to put a tank heater on it. It has been at or below zero here for most of two weeks. Was close to zero yesterday. As a joke I pulled the starter and it fired right up, then stalled. Just like it did at 20 degrees. After the initial start it cranks weak and will not fire. I need to go back thru all the posts on this and see if I can get a clue from the responses. CLEARLY this tractor will start in cold weather. It just doesn't have enough juice to do it twice and I am just not experienced enough to tell why. But it WILL start. One thing I can tell you...it is not a choke issue. Has a new choke cable and is properly adjusted and I know how to use it. 12 volt system, new battery, new cables, starter was checked at shop, new solenoid. I'm having another run thru the previous posts. If anyone has a comment I am happy to discuss it. I feel like this is something simple and I am very close.
 
after you start it, it stalls then won't crank very fast, do you have to recharge battery before the next attempt? Do you have a load tester for the battery? New doesn't always mean good.
 
(quoted from post at 13:09:30 01/07/18) ..it is not a choke issue. Has a new choke cable and is properly adjusted and I know how to use it. 12 volt system, new battery, new cables, starter was checked at shop, new solenoid. I'm having another run thru the previous posts. If anyone has a comment I am happy to discuss it. I feel like this is something simple and I am very close.

If you know how to choke this old stuff then maybe you are killing from electrical.

You should have been able to feather the choke and keep it running if it was fuel.

You need to start diagnosis soon as it quits, check battery voltage at every connection to the starter, you need a starter amp draw test and voltage right then to see what is going on.
 
I have messed with several 300Us,the gas tanks all seem to need a cleaning,the steel gas lines plug up,the carbs will catch any of the crap that makes it that far. None of this has anything to do with you trouble. The first things I would look at are the copper stud on top of the starter and check the solenoid(you did say, pulled the starter rod)also check for a good ground between the starter and the block. A volt meter, or even a test light hooked to the battery cable at the starter will tell you if you have good volts at the starter and if you still do the second time you try to start it.
 
If it was me I would just for the heck of it try a different battery. I have seen batteries do some odd things in the past. If it does the same thing wit ha different battery you may have a bad starter even if it tested good not all bench tester work like they should and ya it may spin up but does it do so with out pulling to many amps so in turn it kills the battery fast
 
In the previous..... 16 degree.. post you said you put on various starting system parts one of which was a battery ...cut off... . I suggested giving that the feel test to see if it is warm or hot after cranking or test it with a volt meter. I don?t know an exact spec of what is an acceptable volt drop across something like that, but I would say a half volt would make it suspect in my book. Another thing I?m not sure has been addressed is timing. Are you sure it is set right? What I?m thinking might be happening is the centrifugal advance may be sticky especially when cold. So you start it up say the engine comes up to half speed and for what ever reason dies. Now the advance has activated in the distributor but is to sticky to return to base timing. So now it cranks slow working against the advanced cylinder firing. During the next restart after one start try unhooking the coil wire and see if it cranks faster then. If it cranks better then I would say the distributor advance is a contributing factor. Good luck!
 
Her is how I start my 350U factory 12 volt in winter.
Have throttle set at speed I want it to start at next time you start it when very cold.This is far faster than you would do in the summer.
Pull chock out when starting it and leave it out more than you would normally like for a few seconds. Maybe 5 to 7 seconds or so.
This tractor was on another property and when I needed it to run I needed it now. The only other thing i can think of is run a jumper wire , by passing the resister when you start yours. If I remember correctly you have a 12 volt conversion but don't have it wired so it starts with a full 12 volts to the coil while cranking. Good luck.
 
Thanks, I operate mostly on luck! As far as I know, the tractor is a 12v conversion with a 12v coil. Don't know about the other thing you referenced.
 
No, actually. I just walk away and leave it. It can be one or more days before I come back and retry. It will do the same thing exactly every time. If temps are more like 30-40 it will eventually start. The slow cranking on second try is a cold weather thing.
 
(quoted from post at 17:16:00 01/07/18) He does. Its an auto electric shop. He put it on a tester back on the bench and
pronounced it ok.

Did he go thru the starter or just test it????
 
That is why I said what I did. I like to do things the easy way so as to make trouble shooting easy
 
Watch this video.This is the way my 350U is factory wired.

https://www.youtube.com/watch?v=PCs5gAZBbxU

Pay close attention starting at 3m20S.
 
One thing I have learned in the decades I have been messing with engine NO TWO engine start the same and one has to learn how to hold there mouth just right and which way to have want levers etc. or they do not start. So when you have as many as I have some times one has to step back and remember how to do what to make it start up
 
I have been following your post on occasion and I have a question. You said that you pulled the starter and the tractor started. What do you mean you say "pull the starter" 300 should have a key switch that you turn to the start position sending power to engerize the starter relay.

I started my 350 this afternoon and with a poor 12v battery it started more than once. 12v the starter should spin that engine over like crazy.
 
I have seen bad new batteries about 5 times. Some produced nothing, some needed to be loaded with the lights for 10 minutes before they produced enough to start, and some just produced about 15 seconds of high amps, then went to 8 volts. I think the battery is bad Jim
 
Thanks! I have been monitoring the new switch. It does not get hot at all. The old switch was terrible. I have a scar on my knee where I accidentally put my leg against it once. So hot it branded me for life. That one is long gone.
 
I don't have that post in front of me but when I say "pulled the starter" that would have been a reference to removing it from the tractor and taking it to the auto electric shop. Back then, the tractor would not start at all...summer or winter...and it had been a great runner. The starter was suspect but passed testing. The kill switch was tested, it was bad but still no start. I replaced all the ratty old cables on spec. What I eventually found was about a half cup of water in the carb and it's never gonna start like that! No idea how it got there. That problem is resolved and the tractor is a good starter...just not when it is really cold outside. That is the current issue I am working on and pretty determined to figure out. I love fixing things. I hate patching things up. :)
 
How about disconnecting battery cable from starter on tractor, connect another battery or vehicle to starter to test, just like on work bench? Make sure you have positive to positive, negative to negative. That should spin just like on work bench except crank engine, also have in neutral just in case it starts.
 
Well,I wish I was there to see it start,because if it fires up,it should stay running.I do know if I push my choke in too soon,my 300u will die.This is why previously I was unsure about your choke operation/adjustment.What I suspect though, is that you have several problems still.If it won't re-crank over you have a battery,or, a battery cable problem;even at 0* it should still crank for a few minutes time. And with a 12v battery on a 6v starter it should crank like a scalded dog.Secondly-I would check your timing,and the advance for proper setting and advancing as rpm increases..Then next-I would go thru the carburetor very carefully.Make sure EVERY passage is clear and unobstructed.No dirt or water.Re-drain the carb and check,never assume.
You should check for 12v at the battery side of the coil while cranking. And another thing,if it won't crank cold,maybe your hydraulic system is froze up,straining the engine,and there by,straining the cranking system.
How does this tractor run when good and warmed up? Will it idle slow,and smooth, down to 400 rpm,and rev up to 2000+ rpm ? Without stumbling,or hesitation? Does the rpm fall back quickly and smoothly when you throttle down? How is the power under a load ? It is even possible that the valves need adjusting,but I doubt that is your problem.
I tried to post the checks I would make in the order I would do them based on what you told us.My 300u is still 6v,and it is an art to start it,because it cranks so slow,but it will always start..Trying to crank the engine,and giving up and trying on a different day just leaves the battery weak and discharged.If that happened you need to put it on the charger and bring the battery back up.Battery cables can be good in appearance,but be corroded internally.Don't assume anything,always check and recheck.Good luck,Mark.
 

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