I’m new to the group and have a D8800 power unit on my sawmill. I think it’s a 1948 the serial number is 6S7218. The other day i had one of the rubber clutch links brake and it broke the pinion shaft off the pony motor. My local cat dealer says the shaft is obsolete but I found a new old stock on line. My question is do you guys think I should fix the pony motor or convert to electric start?  Both routes look expensive but pony motors seem to start better. The main engine runs very good and will start good in the cold. I just worry about needing starting fluid all the time with electric start. 

Replacing the pinion shaft would be relatively inexpensive and a simple fix compared to converting to direct electric start and the associated problems with heating the main engine for stating. Why would you not just replace the broken shaft???

Wombat

I would repair the pony motor, those Cat engineers were pretty smart. I would imagine with an engine that size it probably saws all the time when it's running , with a couple of guys feeding it. I'm assuming it's a production mill, anyway if you are only starting it a couple of times a day and its warm the pony will start it easy. If you are starting and stopping a lot maybe an electric starter would be the way to go. Not familiar with your engine but maybe pony start and electric.
I've had a sawmill in one form or another for 20 or so years, I'd love to see pictures of your set up. Video of it sawing?

I’m totally leaning toward fixing the shaft. It’s just the shaft alone is about 500 bucks and I would hate to get into it and spend a lot of money and need that one part I can’t find. I definitely like to keep old equipment original. The mill is a Lane no1. When everything goes right I can saw 3500 to 4000 board feet per day but I’m still working the bugs out of it.

photos please pictures say a thousand words. if i understand you properly you were starting it when the failure happened.

It was running. I was sawing and one of the rubber clutch links on the main clutch broke and snap the pinion shaft off the pony motor.

I do have the shaft, sent you an email/message.

Here is a video of last fall