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1941 John Deere A

6K views 9 replies 5 participants last post by  Lovesthedrive 
#1 ·
I bought this 41 A this spring and its still giving me fits. I've replaced or cleaned all the filters, replaced all fluids, rebuilt the carburetor, repaired the air cleaner, and still having rotten luck. Still can't get the air fuel mixture right because there is an issue with the low idle passages.....its always hunting. Saturday I was out plowing snow with it and now this morning it won't start. It's got new plugs, good hot spark, timing set on the magneto. I just don't get it. Any thoughts would be welcome. Land vehicle Tractor Vehicle Agricultural machinery Motor vehicle
 
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#3 ·
Throttle Control Rod

".....its always hunting."

Take a look at the parts diagram below.
Text Diagram Technical drawing Parallel Line art


Note the throttle rod (Key 4), 1/4 nut (Key 5), throttle rod end (Key 6), and governor arm (Key 23).

Reviewed the SERVICE MANUAL ON THE JOHN DEERE B TRACTOR SM2004 under the Control Linkage topic and Throttle Control Rod Adjustment paragraph on page 110-10-3.

"If throttle control rod does not adequately regulate the engine speed it may be adjusted. Note that the rod is threaded at the end which is connected to the governor arm and secured with a jam nut. To adjust rod length, disconnect rod from governor lever arm and loosen jam nut. Move speed control lever to the wide open position. Set throttle disk in wide open position. Lengthen or shorten rod end until the rod is 1/2 hole short. Place into position and lock jam nut."

Take a look at the photo below of "Uncle Earl" our 39B.
Green Terrestrial plant Plant


Note the distance between the governor arm and speed change spring is approximately 1/8 inch.

Take a look at the photo below of the choke lever on "Uncle Earl" our 39B.
Auto part Jaw


Hope this helps.
 
#4 ·
Nope. Still nothing. Checked the air cleaner, cleaned it again, pulled the carb, no blockages. Checked the governor linkage to the throttle on the carb, still half a hole off. Pulled the plugs, rolled the flywheel, good spark. Checked the fuel line and the carb while it was off, good fuel flow. I haven't got a clue. Theoretically, with air, fuel, and spark, it should start.
 
#5 ·
How much compression?
Two things left, change spark plugs (they work fine with out compression, yet under compression the spark may not jump at the gap). If plugs dont do it, just for giggles try replacing the condenser. It is possible to have a bad condenser, especially with hand cranked engines. The image below is a typical condenser from a 1968-1972 Chevy C-10.

Auto part Automotive engine part Steel Metal
 
#6 ·
Another thought is to see if it starts with out the wires being inside those metal sleeves. The spark will want to go to the shortest path. If you have bad wires, they wont mind going through to those nice metal tubes our out the at the protector at the top of your spark plug.
 
#7 ·
Moisture

Take a look at the photo below of the compression relief cock.
Plant stem


You might consider checking to see if there is "moisture" in the combustion chamber.

Remove the spark plug wire from the spark plug.

Cover the end of the wire so that there is NO spark.

Remove the relief cock and cover the hole with a paper towel.

Crank the motor over several revolutions.

Check the paper towel for water, antifreeze, and/or gas.

We have a 43B that seeps water/antifreeze into the left chamber.

Since the relief cocks are on the bottom of the block, both relief cocks are opened before starting.

Most of the time water/antifreeze drips out of the left chamber.

If the water/antifreeze is not removed, then the tractor will not start.

Hope this helps.
 
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#8 ·
the parts we get at most tractor stores are JUNK. ive used a brand spankin new set of tisco points and they went bad before the tractor left the shop, along with the 27 tune up's I had to redo because of faultly tisco/calco parts. on deere's ill only use wico points and all others gets standard brand. never had a problem after that in the 4+ years of havin the tractor shop.
 
#9 · (Edited)
the parts we get at most tractor stores are JUNK. ive used a brand spankin new set of tisco points and they went bad before the tractor left the shop, .............. because of faultly Tisco....parts. .
It happened to me on an Allis 175, and I was scratchin' my head, goin' through everything twice, trying to figure out why the tractor wasn't firing right. The Tisco parts they were replacing only lasted 4 hours, and I couldn't believe two sets of parts I a row. Believe me, take Wizzards advice on ignition parts. That was three years, lots of rolls of hay, and about 400 hours ago, and they're still workin' good. I'll never use anything else on my tractors again, and hope they don't quit making them.
 
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