1937 John Deere B starting problems

amtrac

Member
Just thought I would share this with everyone as maybe somebody else has had the same dilemma. The '37 engine has been bored and sleeved back to original specs, the carb has been professionally rebuilt, and the Mag is a new, rebuilt Wico X with lots of spark. This tractor will start every time on the second compression when cold with the choke set at about 3/4, throttle set at about high idle. Runs great, idles great, doesn't foul the plugs. But if you shut her off and wait an hour or so, she just refuses to start, choke or no choke. I finally figured out that this particular engine likes to start with choke when cold, but when warm she only will start with the throttle set back to almost idle. No choke and just a tiny bit of throttle and she starts on the first compression. Took me a year to finally figure this procedure out. I guess these old engines all have a certain way they like to be set up for starting. Are we getting more fuel into the cylinders with the throttle closed? Less air=more fuel? Like to hear the experts comments.
 
Disallowing the expert part, but yes to more better gasoline vaporization at idle settings is due to forcing air flow thru the idle ports found in the throat of carburetor there. They get no use when the throttle plate is wide open and engine is not running to create a decent vacuum here.

Thanks for stating what works for you on a recently running engine. I too went thru a learning curve to restart the old girl when warm. I've heard many times that B doesn't like choke very much, only useful when really cold too.

One tip was shared by a guy at a show when his just wouldn't start for him. Old timer stepped up and asked "shall we?" Sure, have at it. He set the throttle to idle, choke to open and rocked the flywheel back and forth maybe six times bumping compression at each end. Then rolled it over nice and slow and she takes right off. This would load the same air charge with repeated sprays of gasoline in the back and forth mode - your guess is as good as mine as to how many though. But it's a neat trick that really needs more exposure.
 
Everyone is different. And as you found out it can take a lot of experimenting to get it figured out. But then every once in awhile you get one that starts super easy even with a worn out engine ! Go figure ?
 
As stated it seems everyone of the tractors & engines are different on cold or hot start, On our
42 B the Only way it will re/start hot is when ever it is shut down it is brought back to a idle, &
it is choked to death, gas is shut off. This tractor can sit for 10 minutes or ten months it will fire
1st time over 1/4 quarter throttle, 3/4 choke every time. If you stall it, or let it run out of gas
to shut it down, be prepared to pull start it. This is the way the tractor has been since it was purchased
1942 by my grandfather.
 
Lee, Thanks for that trick of rolling the flywheel back and forth. I tried it one time, but must have had too much open throttle. Didn't work for me, but I will try it again with throttle closed if I ever have starting problems again. Reading other posts here on the forum, I have found several that advise starting the two cylinder engines with closed throttle. My 40 standard NEVER needs choke to start and she fires right off cold or hot, throttle set to low idle.
 

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