Thanks very much Hugh.
I was thinking about automating my starting process with a couple of DC linear actuators and an Arduino controller.
I was particularly interested in the timing of the compression release on a Startomatic. However, I cannot use the same starting sequence as an SOM since my starter will not overcome compression from a dead stop.
It has no trouble once the wheels are rotating, but the initial inertia combined with compression is too much.
So my plan would be to .... Open the rack ... allow say 5 seconds for the wheels to spin up ... then allow compression.
During shutdown the actuator would move to the decompress mode ready for the next start.
Some sort of rpm or generator output sensor would be used to confirm a successful start.
Oh.... so your SOM is not working .... that must make you very angry.
In fact I bet you want to get rid of that thing.
I offer to drive from one province over and remove that malfunctioning SOM machine for you. No charge to cart it away. 
Now .... where did I put my ferry schedule 
Hey Veggie, Hugh and others
I don't know if this setup or its parts could make a contribution? I bought it a while back. I believe it to be a SOM unit re-housed in a more modern (maybe '70s) cabinet by a local electrical shop. It was starting a Lister generator on a remote station here in NZ well into the '90s. I bought it from a retired engineer who worked on the station at one time
Check out the pics if you like? If you look carefully I think there are some "spares" in there too - coils? I don't know if SOM bits are common across models - but I'm sure some of you guys will know
Cheers