d4 7u ?

They didn't. .........pony start was an option (if not standard) all the way through the u series and was available on subsequent series as well.

The later series ponies were a vertical 2 cylinder design that operated at very high rpm, and soon acquired the "buzz bomb" nickname! Those things probably hastened the final demise of pony motor start by several years.

Hi, Clydecrashcop.
As I understand it, the U series had pony motor start standard until the end of the run. As Ccjersey posted, pony motor start was still available on the later D4C's as a 2-cylinder vertical motor that ran at about 6,000 rpm and had a strong tendency to 'self-destruct'. Anybody who has a D4C with a 'buzz-bomb' pony motor would be well advised to junk the pony and install direct electric start.

Just my 0.02.

My 78A D4D parts book shows the buzz bomb.

Ted Billups, one of my favorite local cat collectors, told me once. "I bet I've got an engine you've never seen", well he was right. He had a customer that had brought him a buzz bomb from a D6B. Ted went through it to make sure it was tight, then built a stand for it so he could display it. He would start it and run it for us. Pretty neat display.

BP.

I think the best thing about the buzz bomb pony motors is they fit into the same hole as the direct electric starter. Just a shim piece installed in the hole and the starter will bolt right in.

The late series 7U's also came with or could be ordered with in seat start pony motors. I've seen and operated the in seat start pony motor 7u that 7upuller has. It is a real nice piece of Cat machinery. 👍

The late series 7U's also came with or could be ordered with in seat start pony motors. I've seen and operated the in seat start pony motor 7u that 7upuller has. It is a real nice piece of Cat machinery. 👍

The unseat arrangement is really nice. I have only seen 2 of these ever; Glen's and one at auction that neither D4e or myself was able to purchase. I was told by a fellow member that there were not very many of these ever made. Could someone shed light on how many may have had this option, and when were they made available? Thanks! JM

Check my thread to Glen below. Ianoz posted pic's of the set up on his 6U.