Inherent problems with 3020 gas

chas036

Member
I am shopping around for a 3020 gas tractor and I am curious what are some of the inherent problems associated with this model. I have read that the MS aluminum carb was a big problem and should be changed to a cast iron carb. What other inherent problems can I expect?
 
I have a 1967 3020 w/the MS slant sided carb. It starts rather hard but always does start and runs strong. I've heard the same stories about this carb and know NEW replacements are available for over $1000 last time I checked. At that price I will tolerate the one I have.
 
A gas tractor that size will burn a considerable amount more fuel versus a diesel of the same size. Really not an especially troublesome tractor outside of the fuel system. One disadvantage is the engine block is unique to that tractor and the 3010 whereas tractors such as the 2510 have more parts and re-power options. Depending on what you get you may or may not ever have to work on or replace the engine. In some ways a 2510 might be more preferable and the HP is close to the early 3020 but collectors have the 2510 on their radar so it's iffy if you can find one for 5,000 dollars or less as you previously mentioned. A 3020 from a known home would do a lot to alleviate a lot of the fears and maybe they have done as others have and replaced the carb with good luck.
 
That MS aluminum carb. is the main thing I can think of that I had to "upgrade" on the 4020 gas. The rest of the stuff is normal wear and tear repairing and rebuilding. These are over 50 years old now !
Being able to switch the manifold heat baffle from cold to hot is NEEDED in cold weather on these. The 4020 has a block you unbolt and swap it around so it really can't rust fast like the 2 cyl. ones do. I'm assuming the 3020 is similar ? Just make sure it is all there and looks ok ? not sure how easy stuff is to find for gassers and many got scrapped.
 
Just keep your eye out for a cast iron zenith used at a good price and grab it up if you do ! That's what I did. I had the MS alum. one "tolerable" and never really believed all the stories I had heard of them. But I lucked out and found a zenith cheap and gave it a try. Made a believer out of me.
 
We have had a 1966 or 1967 model year 3020 gasoline powered tractor on our farm since the early 1970's. Back then, it was used to plant, cultivate, and haul grain. It had a front end loader attached to it a few years later and had the added task of snow removal, loading manure, pushing silage up and into a bunker silo, and daily chore tractor for feeding cattle. In the early 1980's, we upgraded planters, and that task was removed, then later cultivating. After the mid-1990's, we quit feeding cattle, so the hours put on this tractor have diminished greatly. I will re-state our carburetor experience. It had the cast aluminum MS carburetor until just a few years ago. On the rare occasion of putting it on a dynamometer, it would put out around 67 horsepower. In all the years I remember starting that tractor, it could pretty much always be started down to below zero temperatures if necessary. When starting cold, we did have to run it some with the choke out a bit until the engine started warming up a bit, but generally only for a few minutes. When it was known we needed to start it in very cold weather, it was always inside and would generally be plugged in to aid in starting and warm up. As far as the gasoline burned in that tractor, it has had E10 since our state of Minnesota began blending gasoline with ethanol since the early 1980's. The MS carburetor could not be rebuilt anymore, as I was informed the cast aluminum construction of it had warped from years of heat, so we purchased a carburetor from Robert's in Spencer, Iowa. The tractor currently starts very quickly and easily, and the choke can be pushed in right away once it is running, and continues to run very well. We haven't seen evidence of smoke out the muffler, and it does not seem to foul spark plugs, so it seems it is not over fueling the engine, however it does have a significantly greater thirst for fuel than it had before, regardless of light loads or heavy loads. I used it for some field cultivating (heavy load) a couple years ago and I never thought it was possible to burn 7 gallons of gasoline per hour through that tractor! Other than the great thirst for gasoline, no issues on a tractor we have owned for over 40 years.
 
I have used/help maintain a friend's 3020G for 25 + years. As others point out carburetion is probably the biggest problem. I found even swapping the Marvel USX (aluminum) carb for a Zenith has not completely solved the carburetion issues.

It runs chronically rich at off-idle, then tends toward lean at full RPM. Consequently it has a tendency to foul plugs when lightly loaded, especially in cold weather. When heavily loaded however it runs very well, though it does consume fuel at a somewhat alarming rate.

The other problem is the hydraulics are slow to "wake up" after startup in cold weather. Engine has gotta run several minutes before the 3 point will lift and the power steering comes in.

The upside it the tractor has otherwise been pretty much trouble-free. And it starts easily in cold weather when its diesel companions (4020 and 4430) are DOA unless plugged in overnight.
 
The JD parts book should have the carb. numbers in it. There are several different carb. numbers but I don't know what is actually different about them ? The one I got came from a 3020 by number and someone had added a manual load adjustment and did away with the electric shut off solenoid that I seen on them in the book.
 
I have had mine for 20 plus years. Took it in the shop to get seperated for some clutch work years ago. Mechanic told me that my 3020 had a allis zenith carb on it from a 190 allis I believe. Told me that back in the day the carbs were crap on these and someone figured out that the 190 allis would fit and bolt on. News to me. But I have had very little problems with it.
That being said.. I would prob buy diesel now. if just for the fuel mileage...
 
I'll echo that mention of the manifold heater blocks being rotated winter & summer! Makes quite a difference in how soon you can push the choke all the way in! I have the MS carb on a 1967 and if you push the choke in fully soon as it starts, you'll just have to pull it back out & re-start it! My 1966 & 67 Chevy trucks & my 1968 Chevy Biscayne were all this very same way as well. I've always been told any carbureted gas engine that does not need choke to run or start when cold is improperly tuned & wasting fuel.

Only other problem I've had was the occasional refusal to crank. When the starter button is pressed sometimes it would just make the OIL & GEN lights dim a bit but would do nothing more. If it would crank it would start. Sometimes it just would not crank. No difference between winter or summer. Only known pattern was it never failed to work correctly if jumped or if freshly charged by a battery charger so it seemed a low voltage/current problem. Having read that there was a second solenoid "packaged solution" sold to solve that very problem, I rigged a small starter solenoid from a lawn tractor just to power my original Delco starter's solenoid.

Knock on wood I have so far enjoyed reliable cranking on demand and that's with all the original plugs & connectors including the park safety switch.

I've not had the hydraulic delays mentioned by others but it will get noisy if the hydraulic pump drive coupling is loose!

I find it a very likeable tractor.
 
I'm seeing new carbs for $350 or so with rebuilt being at least that if you don't have the Zenith to trade in for a core. Still a significant hit, but not $1000.

I've got a 3020 gas. It works OK. I did a Zenith carb and electronic ignition. I also moved the battery up by the starter. It cranks slow, but starts (plugged in, in the barn) now at any temps I'd care to crank it. Does suck a lot of gas.
 

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