Unstyled A with Increased Compression

[dunncl66]

Help. I bought a nice Unstyled A with increased compression - something about plated pistons and domed valves. It has so much compression that I cannot pull it through the compression stroke to hand start it. It pull starts ok but I would like to be able to hand start it. Is there anything that I can do as the engine is now to start it easier by hand?

 

[matthies]

You are opening the petcocks right ??

 

[used red MN]

Hello Dunn, welcome to YT! Not a JD guy but doesn’t it have compression release petcocks kind of near the spark plugs? I am thinking plated valves and domed pistons would probably be a more likely description of the mods?

 

[Fixingfarmer]

He does it looks like the left relief valve is open I assume you are opening the right as well?

Some of that piston is already going to be past the hole that is open so there’s a limit to the amount of benefit the petcocks have… all of what’s been “improved” compression wise you will be fighting.

The other thing to check is does it flood because that can make it extremely difficult to turn over as well

 

[dunncl66]

I have a number of old green iron. The petcocks are indeed open. The pistons passing them in the stoke makes sense. After reading a little it sounds like pulling tractor mods of this type result in a pull starts only tractor.

 

[Fixingfarmer]

Or electric start mod I would assume

Approximately the spark plug hole is where the top of the outside edge of the piston stops traveling up (or more appropriately forward in the case of a 2 cylinder) and coincidently is why there’s still enough compression to start the engine with the reliefs wide open and why also once started there isn’t an explosive ball of fire at the petcock. The boom already happened just exhaust gas is being released as the piston goes past.

 

[used red MN]

I have never hand cranked a Deere 2 cylinder but by having the petcock open he should be able the bleed off the compression however slowly it might be until the piston gets near TDC. Then pause a bit and pull it past the position the ignition fires the plug and then get it to fire especially if it has a magneto. Might take some trial and error a probably make some marks on the flywheel to line up where it passes the point of firing maybe it already has that. I might also just be pumping mud.
Earlier today I watched a video of a gentleman starting a Field Marshall tractor that uses a shot gun blank to initiate the cranking. Maybe he could tee something like that into the left spark plug hole and still make the plug work.

 

[Fixingfarmer]

I always figured if I was disabled (mentally for sure at that point if I sold the A with electric start first) or otherwise couldn’t start the B as I got old id put a Honda (or used clone I mean I probably have medical bills) engine on the back step with keyed battery start and a go cart clutch belt drive to the pulley that powered the former belly mower off the pto shaft. Properly shielded of course. Rube Goldberg would be proud.

It would be easier to find a flywheel with a ring gear and to be honest the amount of time it takes to disassemble and put that particular tractor back how it was originally is negligible easily done on a Saturday if you are moving along we are talking 500 bucks (pistons ain’t cheap) that he would probably be spending less than even the find a starter and ring gear plan unless he truly wants to pull with it. Then it gets significantly more fun

 

[dunncl66]

Thanks for all the feedback.

 

[Loosehandle]

Help. I bought a nice Unstyled A with increased compression - something about plated pistons and domed valves. It has so much compression that I cannot pull it through the compression stroke to hand start it. It pull starts ok but I would like to be able to hand start it. Is there anything that I can do as the engine is now to start it easier by hand

Is it in an excellent state of tune? Such as strong spark with impulse working?

 

[mrslesq]

I have a number of old green iron. The petcocks are indeed open. The pistons passing them in the stoke makes sense. After reading a little it sounds like pulling tractor mods of this type result in a pull starts only tractor.

If you have another tractor with a pulley, use a flat belt with a twist in it.

 

[HFP]

I have a USA that is right on this line of being able to start by hand as well. A couple of things I have learned. Make sure mag is working exactly as it should. If you are trying to start on number 1 side and it fires but two doesn't, the flywheel doesn't have enough momentum to get through the number 1 cycle even with the compression release open. Very frustrating when it won't quite go over, but fires every pull. With a questionable mag, I have had luck trying to start the tractor on the number two side rather than the number 1. Something you might try. I also took the stock petcocks out and replaced them with a 1/4" ball valve for compressed air. They eventually wear out, but are cheap and flow air a lot faster.

https://www.lowes.com/pd/Kobalt-NPT-Mini-Ball-Valve-1-4-in/50129814

 

[dunncl66]

Does anyone have a well tuned tractor that won’t hand start and you have to pull it off? I am sure I can improve the tune of this one some but it would be encouraging to know it will work once it’s perfect.

 

[Non-farmer]

OK, I had to look up this whole style thing. I think I understand now, but have a question. Am I correct in thinking that nothing was called unstyled until after they started making "styled" versions?

 

[used red MN]

OK, I had to look up this whole style thing. I think I understand now, but have a question. Am I correct in thinking that nothing was called unstyled until after they started making "styled" versions?

Unstyled JD A on Tractordata
Styled JD A on Tractordata
Wore out is correct this is very .. but if you don’t know you don’t know. To my knowledge once a model became “styled” that was the version that was produced, no backwards steps taken.

 

[Fixingfarmer]

OK, I had to look up this whole style thing. I think I understand now, but have a question. Am I correct in thinking that nothing was called unstyled until after they started making "styled" versions?

You are correct. The manual from 1935 it was just a model B or A.

There’s even some sales videos out on the web where they call the styled version the “New” B with the tin and Power Trol and the kid says it’s not like our old B no no no our new B is convenient and easy to use so my guess is the term styled took awhile to appear.

Within styled there’s a major break between what grandpa called a war tractor (that might be somewhat inaccurate but it’s what he called them and what his is) and late styled about 1939 tinwork appears and 1947 a decent seat and some updating I believe are the splits with engines increasing in size for both A and B

Some of the not making a new model was the war they didn’t allow it I don’t think. Some of it was it’s what people had come to expect they kept it until 1953 long past any restrictions on new models.

 

[Loosehandle]

Does anyone have a well tuned tractor that won’t hand start and you have to pull it off? I am sure I can improve the tune of this one some but it would be encouraging to know it will work once it’s perfect.

I'm alone so pull start isn't an option.

 

[buickanddeere]

Three versions