Well your logic seems very sound to me. I used new pin's on my governor linkage and made sure it was not binding. The governor responds to load ok but is not spot on accurate, nor would I expect it be for every load condition. I'm not sure what latitude the AVR in the alternator head will tolerate when compensating for voltage drop but according to the supplier most generators are set up to run slightly over 1500 rpm to offset the loss under load. Apparently 1520 rpm is acceptable unloaded.
Logic would suggest adjusting the governor to hold up under maximum continuous load conditions.
Under 2.5kw load the governor is maintaining 1510 rpm so not to shabby. I may try fitting an 8mm element pump down the pike. Not a particularly hard modification to do. Thanks very much for the feedback. Much appreciated.
Tempting as it is to raise the rpm to get more power I don't really need it and I really like the sound at 650. Purposeful but not straining.

Thanks for the feedback, much appreciated. I will bear that in mind. My cs still has the original spring but I can't help wondering if it wouldn't be easier to fine tune the governors response if the lever moment was adjustable rather than rely on a spring that's now 59 years old. There is a we bit of pin play at the injection pump rack which I mean to take out with a brass insert. That would make a difference I think in reducing the Rpm drop.
Over reving to get more power ? Tempting but only if i went with an Aluminium piston. Opinions vary on that and I'm not best qualified to make a statement in that regard.
Looking forward to getting the engine bolted down to a good solid concrete plinth and working her hard. How clean is a battery chargers DC output?
Is it spikey or pretty smooth ?

Hi Bob

I'm down under too. Opinions vary on how much I can push the engine but I'm hoping I can get 3.5 kw. I ran out of time to plug in another appliance. It's an oversized Chinese Stamford clone. It's rated at 9.9. Way oversize. But I figure the slight loss in efficiency will be compensated by durability.
I am looking for a DC alternator to charge my battery bank. I haven't built a slab and shed for it yet. The engine does drop RPM a bit under the larger load. Not sure if there is anything I can do about that. The engine wasn't really warmed up when I loaded her up.
I had to hold her down with the loader bucket on my tractor otherwise she would jump up and down to much. But held down she ran smoothly. At the moment it's bolted to a hardwood carriage.

What angle are the pipes supposed to be with a thermo siphon ? I don't have a copy of the manual.

When I first tackled the gib I relied on the " good advice" of someone at the local vintage engine club. This technique involved a lot of buggering around with little wedges and shims which tended to drift up.
So I thought about an easier way and decided to make a very big long wedge with a very shallow angle for maximum power and long enough that I could drive the end from outside the diameter of the flywheel.
So I grabbed a long length of angle iron and cut a long wedge with my angle grinder.
To avoid it riding up while driving I cut it with a bias so that the edge bit at the bottom of the key.
I rocked up at the club with my length of angle iron, tapped it snug on to the gib shoulder and drove it with a small mallet. It worked perfectly. Quick, cheap, easy and no damage at all to the gib key. Avoid the temptation to use a shorter steeper angle. I would suggest making it at least 14" long so it's a nice shallow gradual wedge.
2" wide angle would be about right. That will drive out the gib far enough to get it loose.

Some general information for those who may be interested.
My business is woodworking so I made the carriage out of Aussie hardwood, a species called black butt. Very tough, dense stuff. I mortise and tennoned the frame rather than use through bolts to keep the chassis stiffer and stronger.The frame for the generator is new Guinea rosewood. The belt tensioning bolts are made from 12mm metric threaded gal rod. The cast iron wheels are not as large as I would like but the price was right and they are double ball bearing. Not planning to move her around much once I've built the gen shed. I will cast a raised concrete plinth on the slab to bolt her to.
I've restored a lot of woodworking machinery over the years but this is my first
engine. I saw her for sale at a good price and had to have her.
The top of the cylinder bore was heavily stepped from a broken ring so I got the block resleeved. Pricey but worth the investment. So it's back to stock 4.5 inch bore.
It suffered some neglect in later years by the look of it. The block was totally clogged with rust, the valve seats and guides were needing attention.
Overall condition though was excellent. I tried to avoid over restoring it but couldn't resist polishing the brass and copper. The transfers are not the correct ones for the CS but they were all I could get.
I am not by any means an expert on engines. This is the first big engine I have ever rebuilt.

Yes. I have attached a Yanan single phase generator to it. Need to sort out the rpm because it's running under speed at the moment. Getting Rpm counter this week to figure out how far short I am. The carriage will need to be bolted down securely before I can adjust the governor. She bounces heavily when I try to increase the rpm.
I want to use her for back up generator and battery charging.
May try an aluminium piston down the track to reduce the vertical mass.
Will post a picture of current state of assembly.