I recently posted this conversion on the Heavy Equipment Forum and was told that the people at ACMOC would be interested in it. This is my version of getting rid of a bad pony motor. My son brought the D2 to my place about 12 years ago with frozen steering clutches. We replaced the steering clutches but could never get the pony motor to run without it flooding. My son moved and it was sitting ever since. I decided to see if I could get it running, which I did and 30 seconds later the pony threw a rod. I did my research a came up with three options, used pony motor(hard to find), convert to electric start(expensive), or put on a different gas engine(couldn't find anyone that did it). I decided to try the gas engine. Here is the process was as follows, I purchased a 13hp electric start engine and battery from Harbor Freight($350), a gear similar in size to the one on pony for 1in shaft on Ebay($35), reused the back cover, 40 tooth gear and shaft from pony, made a plate to cover water and hold a carrier for the gear shaft, put the motor in place to mark mounting holes and see what would need to be moved, removed the motor, drilled and taped the mounting holes, raised the hydraulic blocks on fenders 1in to clear the new motors valve cover, remounted motor and made spacers as needed, made a plate for the water port on diesel engine, mounted fuel tank on back side of dash and enlarged the filler hole, modified air cleaner to fit, cut down the exhaust pipe and welded it so it would run from new engine back to intake manifold, cut down the tail pipe and mounted muffler( new motor needed more back pressure), ( due to lack of space for the monster air cleaner) I ran a throttle rod threw the dash and installed a air cleaner right on the intake manifold and built guarding with lubrication points for the gears. To me it sounds easy now but with no were to start it took a lot of trial, error and fabrication. It now starts pretty much starts as it always did. I am attaching so pictures of the process.

I also have pony motor parts for sale.

"Bothborn52" wrote:

I recently posted this conversion on the Heavy Equipment Forum and was told that the people at ACMOC would be interested in it. This is my version of getting rid of a bad pony motor. My son brought the D2 to my place about 12 years ago with frozen steering clutches. We replaced the steering clutches but could never get the pony motor to run without it flooding. My son moved and it was sitting ever since. I decided to see if I could get it running, which I did and 30 seconds later the pony threw a rod. I did my research a came up with three options, used pony motor(hard to find), convert to electric start(expensive), or put on a different gas engine(couldn't find anyone that did it). I decided to try the gas engine. Here is the process was as follows, I purchased a 13hp electric start engine and battery from Harbor Freight($350), a gear similar in size to the one on pony for 1in shaft on Ebay($35), reused the back cover, 40 tooth gear and shaft from pony, made a plate to cover water and hold a carrier for the gear shaft, put the motor in place to mark mounting holes and see what would need to be moved, removed the motor, drilled and taped the mounting holes, raised the hydraulic blocks on fenders 1in to clear the new motors valve cover, remounted motor and made spacers as needed, made a plate for the water port on diesel engine, mounted fuel tank on back side of dash and enlarged the filler hole, modified air cleaner to fit, cut down the exhaust pipe and welded it so it would run from new engine back to intake manifold, cut down the tail pipe and mounted muffler( new motor needed more back pressure), ( due to lack of space for the monster air cleaner) I ran a throttle rod threw the dash and installed a air cleaner right on the intake manifold and built guarding with lubrication points for the gears. To me it sounds easy now but with no were to start it took a lot of trial, error and fabrication. It now starts pretty much starts as it always did. I am attaching so pictures of the process.

Wow, that is really a great project. You must have created a complete sealed compartment for the gears?

Thank you so much for taking the time to post this especially with the great explanation.

Thanks for sharing that. I have wondered about using the CAT pony as a gear reduction unit - removing rods, pistons, cams, etc. Drive the pony crank with a modern engine via a belt mounted on the fender.

Of course the purists would cringe - congrats for completing the project.

As the late Fred Hedrick would say; You can do what you want, "But It Won't Be Original" Bill Walter

Interesting project. I enjoyed seeing your creativity. It would have been cheaper and easier to keep it original. Even in my cat poor area I have found my quota of spare parts.

"STEPHEN" wrote:

Interesting project. I enjoyed seeing your creativity. It would have been cheaper and easier to keep it original. Even in my cat poor area I have found my quota of spare parts.

I looked into that but when the rod went it scored the cylinder wall, took a chunk out of the bottom of the cylinder wall and damaged the crank shaft. Basicly I needed a whole long block, which I located in Idaho for $800 not including shipping.

"Bothborn52" wrote:

I looked into that but when the rod went it scored the cylinder wall, took a chunk out of the bottom of the cylinder wall and damaged the crank shaft. Basicly I needed a whole long block, which I located in Idaho for $800 not including shipping.

Sticker shock got you! That's how I bought my first Cat for $300, guy was told that the only way to fix the steering was to bust the final drives for steering access & get used ones for $1500. Luckily the people in this club helped me get the drives off in one piece and find the parts I needed. Complete running machines have been bought for $800 and scrap price is way down right now. Advertise here for whatever you need & you will get more help than you can stand.

Sad part is, you made it look too easy! Thanks for sharing! Don't worry about originality if it gets the job done for you instead of sitting broke down!

Personally, I like it.

BP

nice job looks clean. did you have to do much adjustment of the pinon latch or dose you out put RPM match the old motor with the new gearing. i will say it would be nice to have a recoil some days on my one pony lol