John Deere Two-Cylinder Diesel's...How Pony Motors/Starting Engines Work

[@weirddeere]

One of the best and most accurate explanations of a Deere V4 pony I've seen yet. Most people don't really understand them very well. I've had two apart. A fun but expensive adventure

[@rogercarrico4975]

I'm impressed with how good of shape that tractor is in. Great candidate for restoration. Can't wait to see it all finished 👍

[@dirtgrainsteel]

Yes we got lucky finding this one I cant wait to get it running

[@danw6014]

Wide open the little pony gallops at 5500 rpm. Both cylinders on each side fire together. It was actually the first engine John Deere developed from scratch.

[@dirtgrainsteel]

Cool!! Thank you!,

[@danw6014]

@@dirtgrainsteel I have a 70 diesel with the little pony, and a 730 electric start. I'm not sure which one is more trouble. Hahaha.

[@bluegrassman3040]

@@danw6014 my dad and his brother used to have a 70 with the pony motor. He said it stayed blowed up most of the time, so they would have to pull start it.

[@danw6014]

@@bluegrassman3040 cost as much to overhaul the little pony as it does to overhaul the diesel.

[@martinbenton742]

That is why I love the 720 pony start tractors. I'll have another one....someday.
Doc

[@dirtgrainsteel]

I want to find a Black Dash 720 next and a 730

[@TimothyFluegel]

Awesome video. I never would have thought that it would circulate the engine coolant. That's brilliant lol.

[@dirtgrainsteel]

Yep it was a great idea

[@davidhess3284]

Most people are unaware of it but in 1958 electric start was first offered on the 720's. I've only ever seen one and that's the one sitting in my barn. It's hasn't been converted from a pony start. It's all factory. I farmed with it until it cracked a piston in 2000. I hope to get it running again soon. It was my dad's tractor and my son is very interested in it so hopefully it will stay in the family for a long time.

[@sawsurgeon]

We too have a factory original electric start 720 on the farm here in Southwest Michigan. Ours has been in the family since '85 or so and is now used primarily for running our 337 Deere square baler and odd jobs throughout the summer. About fifteen years ago electrolysis won the battle against a cylinder wall, thereby causing us to overhaul an otherwise perfectly running engine. At that time, the only parts we had to source outside of Deere were the wrist pin bushings. Fortunately we found some Cat bushings that served perfectly after a little machine work. Hopefully you have had an opportunity to tackle your project.
If you haven't yet, look into refreshing the fiber discs on the cooling fan. They are often neglected and ours failed shortly after the rebuild. Best of success to you, Tedd

[@garybarrett6581]

another good thing with phony motor you can build oil pressure in the big motor before starting whitch l thing on a cold morning this a life saver on the big motor!! l be watchin!!!

[@dirtgrainsteel]

Yes thank you for bringing that up I know I missed a few things but some of these videos I do alot of these videos un scripted so I forget to mention a few things lol

[@kenhanson4015]

I had a 1954 John Deere Model R with the two cylinder pony motor. It was electric start with choke, two pull out knobs on the left by the clutch and compression release levers. There was no throttle, it ran at 4400 rpm until you closed the gas lever to kill it. I miss my tractors. I sold all of them and started buying antique cars that you can do a lot more with.

[@demontrain4438]

Thank you for the breakdown on how the pony motor works. Good explanation on the benefits of a pony motor

[@dirtgrainsteel]

Your welcome!!

[@jimmybland6519]

In the early years Cat and John Deere worked behind the scene at lot on development of motors and transmissions.

[@kerrywitherspoon1257]

grew up manitoba cold winters 730 would always start a must with the catle 61 now love the 2 cylinders have d m g b br all run restoreing is such a great hobbie love your video

[@dirtgrainsteel]

Wow what a awesome collection!!!!

[@41Zman]

Some of the Early Ihc hit miss tractor had a small pony style motor to help start the big main engine

[@deanbrown4512]

Thanks for the lesson, never knew any of this. I wasnt around the Johnny Poppers

[@dirtgrainsteel]

Your welcome!!

[@ianpaterson5000]

My uncle farmed here in South Australia. He used a late model 2 cylinder John Deere for many years with its unique exhaust sound.
It had a pony motor.
When he replaced it with a 6 cylinder Chamberlain I remember him saying the fuel usage increased significantly.

[@djparadiseupandcomingvideo1104]

I love this video very interesting stuff my dear friend

[@AustinRBa]

Interesting that they prevented fuel flow instead of pulling ignition on the pony if oil pressure wasn't built up yet. I'd guess that's to prevent flooding the pony before oil pressure is built up? Good video, love these little v4 puppies.

[@MilkMan608]

Also shuts off fuel supply to prevent filling the pony crankcase with fuel if the carburetor float seat leaks.

[@koryleague8833]

Great explaination. Thanks I didn't realize it did all that. I always just thought I was a gas motor to turn the diseal, kinda like a gas version of an air starter. Thanks for sharing your knowledge. Maybe today's manufacturers could take a lesson.

[@dirtgrainsteel]

Your welcome!!!

[@GosselinFarmsEdGosselin]

I believe you are correct.. cat and Deere.. cat I believe had the first one..
Looking good!
Thanks for the video!

[@dirtgrainsteel]

Thank you for watching!!!

[@AndrewHCann]

Excellent video , yes pony motors are excellent helpfull too and hope see more too!

[@dirtgrainsteel]

Thank you!!! You will see more!!!

[@edwardyounkin2660]

Thanks for explaining how a pony motor works awesome video!!

[@dirtgrainsteel]

Your welcome!!!

[@peteschiavoni]

Great explanation. I’m learning so much. You really have the coolest projects!! The lighting has been phenomenal!!
Cat is the only engine I ever heard of with a pony motor but I never saw or played with one.

[@farmerbill6855]

Cat made their own pony motors. Waukesha had pony motor diesels. Early Allis diesels had pony motors but they may have been Waukesha.
Best regards from Indiana.

[@cooperbybee4308]

Thanks you very much for the informative video. Most guys just want to show off their antique pony motor tractors and don't share their knowledge.

[@matthewschlichting5962]

I agree with you no matter what color you like keep them as original as possible

[@dirtgrainsteel]

Yep exactly!

[@galendrake4528]

The clutch element in the pony motor that has the 3 balls in it is called an overrunning clutch. When the main engine starts while the pony motor is still clutched in, it allows the main engine to establish a disconnect between it and the pony motor as now the rpm of the main can exceed that of the pony motor and disengagement of the clutch is possible without gear grinding or overspeed damage to the pony motor. The electric starter on Honda motorcycles also incorporate an overrunning clutch that is the only separation between the starter motor and the engine. Some technologies last through the ages...

[@keltonwright7]

From my understanding John Deere used CATs pony motor in the model R, then they worked together and Deere built there own pony motor for the 80, 820, 830. Hence the difference from an opposed 2 cylinder pony to the V4 cylinder pony. Some say that the 2 cylinder pony is far better then the 4 cylinder, but never been or worked around a 2 cylinder one to say myself. Also, a lot of die hard Deere fans at the time called the V4 pony Twin 2 cylinders because they didn't want to admit that Deere was switching to engines with more cylinders then 2 like other competitors like International.

[@dirtgrainsteel]

Now that’s interesting thank you for sharing this!!! What i find very interesting is the timeline of the new generation tractors and how they were still building 2 cylinders while they were building and testing the 10 series tractors i watched a TH-cam video about it and I guess the 10 series were used for 5 crop season at the John Deere test farm before they were ever offered to the public so that means 2 cylinders we still being made up till then

[@bluegrassman3040]

@@dirtgrainsteel I’ve been told that JD was about to go bankrupt by the time they stopped making the two cylinder tractors. The 4 cyl and 6cyl engines were what saved them, so I’ve been told.

[@bnelogic6237]

Thanks for that info. Very informative.

[@dirtgrainsteel]

Your welcome!!!

[@stewartalbert3523]

When i was a teenager , the farmer i worked for bought a 730 diesel 1958 model with electric start . At 0 degrees we could not even pull start that tractor !

[@Des-kh-41]

Lots of Russian tractors and big trucks had 2 cycle (I think) pony engines based on what I saw on TH-cam…

[@robertpayne2717]

My dad had a 730 diesel electric start he bought in 1959 or 60 John Deere used a mechanical linkage to the valve train that when starting you depressed it with your foot and it partially opened the valves to decompress the engine to aid the diesel in spinning over. And as soon as you released the decompression pedal it would begin to fire on diesel. It was not always easy especially on very cold days. I think that John Deere sold most of these in the lower 48 states and continued to sell pony motors starting engines in the colder states and Canada. Most of the other diesel tractor brands IHC, MOLINE, ETC SOLD ENGINES WITH GLOW PLUGS AS STARTING AIDS ON THEIR TRACTORS.
WE HAD AN 560 INTERNATIONAL THAT HAD GLOW PLUGS BUT, AS I REMEMBER THOSE GLOW PLUGS WERE A PROBLEM BECAUSE OF THE AMPERAGE DRAW ON THE BATTERIES.

[@danburch9989]

Waukesha used pony motors to start their big engines that approached 3000 ci displacement. There's a museum in England that uses a steam powered "pony motor" to start a much larger steam engine that was used to pump water. Those are interesting videos to watch.

[@keithtopliffe3741]

Great video. I've got two 720s I'm going to restore.

[@dirtgrainsteel]

Thank you!!

[@tomottmar7554]

I used a 70 diesel for having for many years

[@willmarshall3552]

Actually, the engine RPM was regulated at 5500 for the v4. The 2 cyl pony for the R was regulated at 4000 RPM.

[@adiamondforever7890]

I had a 720D and a 730D., loved the pony motor once I could get to run reliably (6v Harley coils instead of Wico magnet coils). I can get the book, but remember 15 or 15.5 hp at 5,500 on 2" bore and 1-1/2 stroke ala Briggs and Stratton. Memory is a fuzzy thing, and that was 50 years ago plus a few. 730 was electric with 4 size 1 batteries under the seat

[@gregleachman9557]

we had a 1948 IH TD 14 crawler with a pony motor. I understand it was a WD 9 tractor engine

[@dirtgrainsteel]

I'm glad your brought this up I forgot got them crawlers had pony's

[@RG-nv1eq]

I d,ont think they were pony motors.Instead they had the main engine start on gas then switch to diesel

[@gregleachman9557]

@@RG-nv1eq thank you for "kick starting" this old boys memory. As I remember you are right a spark plug on each piston X4. Okay left lever spring loaded down, chock button to start on gas. 30 seconds diesel lever up......whoops gas lever down, back to gas. Another 30 seconds both levers up, diesel runs. Does that sound right? Drove TD9/TD20 on Cat train in northern Manitoba winter of 1969 and had to fix on the trail many times. I enjoy watching Shannon Farms (my wifes first name also) with their old school equipment and how they fix and move ahead with their projects. I have subscribed and liked!

[@theot4077]

Interesting -- Pony Motor V4cyl. Like it.

[@je9732]

My understanding is cat and John deer worked together developing the R. They had an agreement cat would do construction and deere will do farm. Fast forward deere got into construction and farm equipment

[@AndrewHCann]

Ford had pony motors with Detriot Desiel motors in Highway Transport 18 wheeler tractor in 1970's to 1990 in one's called Aero Macks!

[@willmarshall3552]

To clear up a point mentioned in a comment, commenter stated the the v-4 pony motor fired 2 cylinders at a time, one on this side and one on that side. While true, It is wasting a spark as many systems now do. How it happens is 2 sets of points set at 90 degrees of each other fire the plugs in an obscure fashion. Each coil fires both plugs on one side, the other set fires both plugs on the other side. Now, first set of points and coil, fires both plugs on one side firing one cylinder, as engine rotates 90 degrees the other set fire one cylinder on the other side, yet it fired both plugs. Then the engine rotates 270 degrees and the first set then fires both plugs on the first side igniting the 2rd cylinder on that side, or 3 cylinder in rotation of firing order. Engine then rotates 90 degrees to fire the last cylinder in rotation, then rotates 270 degrees and the process starts over. Ain't that neat, at a slow idle the engine sounds almost like the 2 cylinder tractor it's trying to start.

[@KStewart-th4sk]

Wow thanks, JD tech or enthusiast? How do you know so much about how the V4 pony operated?

[@johnsushchyk7933]

Thank you for your information

[@dirtgrainsteel]

Your welcome!!

[@donharris4246]

good job , i have a R 1949 is the 2 cylender work like the one you are showing mag has been rebuilt by rebuilt mags rudy calin startes has been rebuilt engine has been rebuilt new battery still will not crank hope you can help

[@artillerest43rdva7]

pony motor is such
a great method to
start the old diesel
tractor motors. pre heats in cold weather,
makes it so much
easer to get it running,
how do you start the
pony motor? electric
starter?

[@dirtgrainsteel]

Yep just a small electric starter

[@oldamericaniron5767]

Lord Muck has video on Belarus crawler with single cylinder 2 stroke pony, I’m thinking 2stroke turned over easier in their super cold winter.

[@dirtgrainsteel]

Ill have to check that out!!!

[@Mopar-Pioneer]

Excellent explanation.

[@dirtgrainsteel]

Good glad you enjoyed!

[@scottpecora371]

You eloquently explained the benefits and advantageous of a pony motor versus electric start on the main engine. Do you know if the pony motors were two-strokes or four?

[@dirtgrainsteel]

It's a 4 stroke engine

[@outlawr-dk3sp]

The farmall MD didn't have a pony on it but was a interesting design also. Boomhauer showed me his once that was a interesting explanation to say the least lol

[@scottrayhons2537]

That had to quite a task to invent an engine to start on gasoline and be able to switch it to diesel while it was running. Back when IH made dam good tractors and implements.

[@knothead8251]

A Chinese air heater works well too for heating the intake àir...plus you can use it to heat your feet

[@tray1785]

I’m not we’ll versed in John Deere pony motors but the cat ones don’t circulate water unless they are spinning the diesel motor so you run the risk of overheating the pony motor if you’re not careful

[@andrewklahold2880]

I am working on a d8 cat just gotten pony engine mounted back on

[@apismellifera1000]

I saw a video of an old bulldozer that had a little two stroke starter engine that would start the big diesel.

[@MegaRiffraff]

Later model semi trucks have pony motors on them that ru heat and air , also in cold weather i could start the APU unit and let it run a few minutes and it would heat the big engine and the cab , they were great when they worked 🙁

[@tomottmar7554]

About all the russian diesels use a 2 stroke single cyl pony

[@ericbrown375]

Using the recommended 30w Non-detergent oil ,, does your oil turn milky looking ?

[@dehoedisc7247]

I reckon that the term "pony-motor" just sounds cool, even though it is a pony engine.

[@billcallahan3104]

My pony motor on my 70 only has 1 lever.

[@donharris4246]

why or what wou;d cause a pony motor not start ? has been rebuild , new mag turn over but will not start help!

[@dirtgrainsteel]

Is it getting fuel?

[@donharris4246]

@@dirtgrainsteel I will have to check if it ever stops raining thanks for getting back to me

[@adiamondforever7890]

timing, fuel, compression. It is always one of the three

[@scottrayhons2537]

​@@adiamondforever7890needs ignition also!

[@adiamondforever7890]

@@scottrayhons2537 You are correct, I put timing as a lump, especially if it was overhauled, and the cam could be out of time to the crank, the ignition could also be so out of time to be absent, or on the wrong stroke. My old 720D had the v-4, it was like 4 Briggs and Stratton 1-1/2 hp engines in one block (2" bore, 1-1/2" stroke). I had to replace the magneto coils with 6V Harley coils mounted outside of the magneto box to get the engine to be reliable. Had issues with wet fouling the plugs. One plug was no fun to pull. The new coils put some life into the engine. Have fun

[@bobsmalser8304]

More importantly, it'll start without undo wear and tear.

[@bethmotgomery2662]

I'd still convert it to a 12 volt starter anyways!!
It's more efficient than wasting gas for a diesel.
Or wasting time to start up a gas by hand.

[@bethmotgomery2662]

That's why I love them 12 volt electric starters and WHY I HATE THEM PONY PEST MOTORS!!!!!!!!!!
I'VE ALWAYS HATED EM!!!!!!!!!

[@willmarshall3552]

Just a small note, why they used oil psi to open gas valve, even if you manually shut off gas, gas cannot flow to the metering valve. There is no carb gas bowl, gas flows direct to metering valve. Reason? Even if carb had a bowl, the vibration from the diesel would tend to cause the pony motor to flood causing hard starting.
Another thought, Cat and John Deere were married at the hip for a few years. How about that!!

[@dirtgrainsteel]

Awsome thank you for the information I appreciate!

[@weirddeere]

Cat and Deere actually sold construction equipment paired together in the '30s and 40s, to complement each other's equipment lines

[@hubertrobinson8825]

A 4cyl pony by the look and the size couldn't it be converted to run a small tractor by itself

[@BIBSTERSrepairshop]

Wanted to work on my tractors had to work on my truck not nearly as fun

[@dirtgrainsteel]

I had to end up making bird feed and bagging corn today I had a good last few days of sales and my stand was getting empty so I had to re fill so I didn't get to do my tractor work today

[@BIBSTERSrepairshop]

@@dirtgrainsteel a busy day of sales is always good

[@dalekrueger1175]

A D2 D4 D6 used a opposed twin starting engine, a D7 D8 D9 used a upright two cylinder, Cat built their own starting engines

[@dirtgrainsteel]

Thank you for the Information!

[@ozz5350]

👍👏👏👏

[@dieselrotor]

Why would anyone in they're right mind delete a pony motor ?

[@dirtgrainsteel]

The Amish like to do it for some reason

[@adiamondforever7890]

Parts, or lack there of

[@brianrvd]

4000 rpm idle, 5000 rpm wide open.

[@dirtgrainsteel]

Thank you!

[@donharris4246]

by the way this is on a 1949 R

[@edwardbrimmer5678]

4000 -5500 rpms

[@dirtgrainsteel]

Thank you!

[@johnlosey5186]

R had an apposed two cylinder

[@ScottKramer-me2bc]

Lj

[@jerrypegram4352]

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