D6 pony motor compatibility with D2

Hello

I have a D2 5U with a pony motor that is past its prime. Recently, a running pony motor off of a d318 power unit was posted on FB marketplace in my area. I didn't think a pony off of a bigger engine like that would share any similarities with the pony on my D2 but the pictures have me wondering. Is there any chance I could make this pony work on my machine? Figured I'd ask the experts.

Thanks

there nothing in common between a d2 pony and D6. Not adaptable.

I am not an expert, but as Brian18a said, nothing compatible. There are some early J series pony motors here on the West Coast that you could adapt to a U series (so I am told). Sad part is that a pony motor can get expensive to overhaul. Good luck. JM

So what is the issue with your old one on the D2? Sloppy bearings? Compression? No start? You would be amazed how long you can nurse one along. Parts are out there, but it can get costly sometimes. JM

I'm in NE Iowa which doesn't see a lot of this stuff show up for sale very often so something that may have worked was well worth posting on here.

The main problem with the old pony is really bad main bearing end play which I hear is a good way to break the magneto arm off. This tractor was my grandpa's for 65 years and he was no mechanic so I know that thing has been rough for a long time but somehow it worked for him. It also seems to be leaking oil out of the rear main seal. I haven't started it in a couple years because the pinion latches no longer work (those little bolts fell out.) so we've been pull starting the main engine. Of course I would fix the pinion issues if I had this pony off for a period of time. But I know with a little bit of tinkering it would go again if I wanted it to. It always took some work to get the electric starter to work and lots of carb choking but once you got it going it ran strong. Maybe it's worth trying to do a rebuild?

I also have a 5J D2 parts tractor with a pony without main bearing end play that I could try to use. I would have to move the old carb to it as well as the electric start and probably the magneto. Maybe using that 5J pony as a base and filling it out with components from my 5U pony is the way to go. I'm just a 23 year old farmer with a Squatch253 Youtube education as far as mechanical stuff goes so I'm not sure if a pony rebuild is beyond my limits or not.

Thanks for the replies.

It sounds like you have the best education and parts to make it happen. If I was 23 years old I would go for it. Have you no hill to park the D2 for a roll start?

J and U series pony motors are swappable. You just need to swap some of the external components from one to the other. Things like the exhaust manifold etc. can be different but they'll bolt right on to the other engine. These engines are very simple so if you felt comfortable with a lawnmower engine, you're not far off handling one of these. If your 5J crank float is within limits, has good compression (for a pony, bugger-all compression is still good : ), then just swap the external components. You'd only swap the carburettor and magneto if the 5U items weren't in good shape. Otherwise you don't need to swap them. Another option is to redo the main bearings to reduce the end play. For that, all you need to do is buy a new pair of dowels, then rotate the main bearings and bring them inwards to reduce end float (crank must be centered axially between the two cylinder bores), and drill a new pair of dowel holes. Some new gaskets and you're back in business. That way you'll have a good spare pony sitting on the shelf. If you start with figuring out what the 5J pony needs, get it ready to fit, then just swap the whole thing over and re-up the pinion, you won't be down for long. Then you can do up the 5U at your leisure.

Currently I have my dad pull the D2 with a tractor chained up to the blade to get the main engine started. Works pretty well in warm weather. But I would really like to be able to use the pony engine to start it like my grandpa did.

I think your idea makes a lot of sense Neil. Especially because it would require the tractor to only be down for a short amount of time. It would also allow me to clean up the other minor issues with the external components along the way. Youtube videos from people like Squatch and LAOL should make the process that much easier. And, of course, the people on this form will be there too.

Once again thank you for the replies.

The d6 and d4-2 pony motor parts are not interchangable and am still have 2 set main bearings 4f9416 - 020