John Deere carb rebuild .. Just don't do it

[redneck1]

Some of you may remember over the winter I got involved with a church project to buy a john Deere tractor and it ended up with me owning a 1952 model A that was surplus to their wants .

over the weekend I took it on myself to rebuild the duplex carb that came on the late model A tractors .
I'm just going to toss this out there .... If you own or are thinking about buying a two cylinder with the duplex carb that needs rebuilt .
Send it out to a professional and pay the $500 .
Wow are they a huge pain in the rear to rebuild , there are 8 blind ports that you have to drill out ( from the outside ) and its a white knuckle endeavor for each one hoping you have the right location .
If you don't drill the ports there's no way in heck you'll ever get things clean enough to work right no matter how long you soak it in dip .

Like many others here I've rebuilt a few carbs over the years and don't find them particularly complicated or intimidating .
But I can say without embarrassment that I will never again rebuild a duplex john Deere carb .

15 hours of double , triple and quadruple checking every thing pretty much did me in . and it still needs put back on the tractor and tuned .

Just don't do it

[smoked turkey]

redneck1 I think you are one heck of a good mechanic to have tackled the carb project. It sounds very complicated. I think you should reward yourself for doing it by taking most of the $500 you saved and applying it to your next gun purchase. That might make it seem a little sweeter.

[tja6435]

I rebuilt the carb for my JD Model 60 (1955), I used brake cleaner and an air compressor to clean out the bypass passages, I didn’t think it was too bad. Took me 6 hours or so. The tractor fired right up once I got it back on.

The tractor came with our property, had been sitting since about 1992. I put about $2k into parts, tubes and tires and now it’s a beast, I have to wear ear muffs or plugs if I’m working it hard.

[redneck1]

You should count yourself very lucky from what I've read very few manage to get the carb clean enough if its gummed up from old gas .

Being nervous and not wanting to buy another carb I spent about an hour on each port , small drill to make sure I was in the right area , then moving up a tiny bit in size till I had them open enough to be sure I was close to center .
And I had to make a new throttle shaft and bushings the original was pretty worn and I'd have never gotten it to not leak air .

[SOFMatchstaff]

If you are feeling all mechanical and such, I got a injection pump on my 450 tracked loader that needs some tender wrenching... Got a kit ordered and will get at it next week. I did the injection pump on my M35 Duece and it runs good now, got lucky I suppose..

[redneck1]

Good luck to you . My one and only experience with rebuilding an injection pump didn't go well .
A 1980's vw after the rebuild it would idle and Soon as you hit the throttle it would run away .
Thankfully the only diesel I've had since then has been pretty reliable for the last thirty years and I haven't had to try my luck again

[Mk42gunner]

I've been lucky. The only old carburetor that I have had to give up on was the Zenith that was on my Allis Chalmers WD. From what I remember the Zeniths need to have the float set to where it is almost flooding when it is set right.

Long story short, I went and got a Marvel Schebler carb for the WD. Much easier to work on, I took three junk ones apart and rebuilt them into at least one that worked sitting on my tailgate at Austin's salvage. It has worked fine for the last fifteen years.

But I never worked on one for the old Johnny Poppers.

New small engine carbs? Might as well buy a replacement from the get go.

Robert

[Bmi48219]

Dad had a 420-W. I had to break it apart to replace the small clutch disc return spring. Lot of work for a 90 cent spring & ball. I still have the JD parts bag it came in. Two years later it started running rougher than a two lunger should. After a few false moves I finally looked at the distributor advance. The lube on the shaft had dried to the point the weights wouldn’t swing out to advance the timing. That old JD taught me a lot.

[Land Owner]

DIY has pluses and minuses. One plus is satisfaction in a Job Well Done. Another is avoiding a $500.00 repair bill. A minus is the hours it took to do the job right. Another is the stress in not knowing if or when a slip might set you back to square one. If the DIY adventure was taken lightly, with no forethought to "what could go wrong" under a considerable pressure that a slip here or there might lead to disaster and discouragement, it wouldn't have been an adventure at all! Anybody can "muck it up". It takes a special "Somebody" to follow through to completion and satisfaction - with a story to boot!

[William Yanda]

$500 for 15 hours is a decent wage. Congrats on completion.

[redneck1]

It takes a special kind of person to work on old equipment , I'm learning that I am not that person .

Went out to put the carb back on , scraped the old gasket off the intake and found a crack in the flange .
Broke two bolts off removing the intake so I could tig weld it up . then enjoyed an hour removing broken bolts .

I got the crack fixed and everything put back together . still haven't tried firing it up and tuning it yet . I might as well dig up some new points and plugs while I'm at it .

[redneck1]

So I managed to get the old girl running properly today .
Thanks to fuel injection I seem to be losing my ear for carb tuning .
It took me awhile , I ended up having to run it up the road a few times to get it under enough of a load to get the high side adjusted right .

Only thing left to do now is either buy a couple 6v batteries or do something neater then the resistor and diode I have rigged up now to use a 12v battery .

[Mk42gunner]

Kind of depends on what you have for a generator or alternator.

My WD sat for several years between the time Grandpa went to a nursing home and I retired from the Navy. somewhere in there some rectum stole the generator, voltage regulator, and dash panel from the tractor. I got the dash from the parts tractor I bought, and an alternator from an early 80's Datsun pickup. It wires up just like a three wire GM alternator. and is small enough in diameter that the corn picker shields would still fit on, if I were to get a mounted corn picker. The wide belt even works with the stock pulley.

For the ignition resistor, I told the kid at the parts store I wanted one for some mid sixties Dodge.

12 volt batteries are a lot more common, and probably cheaper than six volt ones are now. The original starter works just fine on twelve volts.

Robert

[redneck1]

As hard as it might be to believe , local parts store has 6v batteries .
Price is pretty much a wash with a good 12v battery .
650 cca 6v are $65 each , I'd need two . A good 850cca 12v. Runs about $120 .

The generator is putting out 8.6 volts so for the moment it's working .
I guess the gamble comes with just how long will what looks to be the original generator and voltage regulator continue to work .

I'm about at the limit of what I want to dump into it money and time wise , I should decide what it's fate is going to be before I get to far into it . Chances are it's gonna find a new home

[KCSO]

I addition the carb bodies tend to crack and if you have a cracked body you just have to pony up for a new carb. Back when you just went to the local implement dealer and rummaged in the junk pile but no more!

[Finster101]

The way you are talking redneck1, does the local parts store have "FOR SALE" signs as well?

[megasupermagnum]

I rebuilt the carb for my JD Model 60 (1955), I used brake cleaner and an air compressor to clean out the bypass passages, I didn’t think it was too bad. Took me 6 hours or so. The tractor fired right up once I got it back on.

The tractor came with our property, had been sitting since about 1992. I put about $2k into parts, tubes and tires and now it’s a beast, I have to wear ear muffs or plugs if I’m working it hard.

Not that bad? Took 6 hours? Sounds pretty bad to me. So much for the "they used to be made to be worked on". I have worked on very few tractors though. About the only thing I've worked on comparable to this would be a small Alice Chalmers of a similar year. The carburetor on that was so stupid simple, I can hardly believe it runs as good as it does.

The thing that kills me on these old tractors is that ergonomics was not a concern at all. While the small metal seats are usually surprisingly comfortable, the spring deals for "suspension" are a joke. My dad recently got his Farmall H tractor back that he bought for the family farm when he was a teenager. It is fun to putt around, but the ergonomics are a joke. The shift pattern is backwards, and the shifter is on the left side underneath your knee. I'm 6'5", so I just move me knee, and shift into a gear. Shifting on the move would be tough. The starter button they put behind the steering shaft. Not sure what the idea was there. I suppose a size 4 shoe might be able to hit it, certainly not my size 15. The steering wheel sits right in your lap, I can only imagine what it must have been like for my dad running that for real work in a field for hours. Ok, I'm rambling now.

[Mk42gunner]

Most of the old tractors had straight cut gears. No shifting needed, just start off in the gear you want.

Back to the JD. If the generator is still working as you say, I would buy a six volt battery and coil and run it the way it was meant to be ran.

Robert

[Mal Paso]

Ergonomics? My '51 Power Wagon has the accelerator pedal on the transmission hump. The original owner drove it to LA and back. Engine redlines at 47 MPH. It's got Cruse Control (hand throttle) if you're on a constant grade. Crash box transmission, 6 volt, all the good stuff.

[redneck1]

While I paint a nice rosy glow on the picture I do forget to remind myself and others this is still a uhmm ... junky tractor that sat for about 30 years before I got my dirty mitts on it last winter .

The only real difference at the moment is that it runs now .
The sheet metal isn't horrid , but it isn't good either , tires all suck .
Fuel tank might be saved but it would likely need more effort then it's worth .
And now that is been run up to temperature a few times the radiator's bottom tank is seeping a bit somewhere I can't see .

But it does run rather well , much better then i ever thought it would .
And it didn't end up at the scrap yard it was headed to so I'm rather pleased with that .