Yep, the cylinder and head are far away from the crank and very little heat is conducted.
Also, unlike modern engines, the CS style does not circulate oil up to the valve assembly in the cylinder head where it would normally pick up a lot of heat. So, depending on service duration the crankcase oil is also susceptible to condensation and water gain as it does not get hot enough to boil off the moisture.

Follow up...

After much digging around I concluded that parts for these engines are getting much harder to find.
Changfa owners should gather spares while you can.
One source that I did find helpful was AliExpress (Similar to Ebay).
There were several online stores there which carry Changfa style parts.
They come and go.
I saw gasket sets, pistons, sleeves, and fuel injectors from several sellers.
https://www.aliexpress.com/

Hugh,
Nice pictures, I especially like your design for tensioning the belt on the PMG Generator.
A hand crank !   Well done.

I’m all in for a starter generator, I would like to get one.

If your are running the starter/generator off a 23 inch flywheel and with a 2 inch pulley on the starter/generator, that’s well over 7000 RPM. Seems like a lot.

What is the output voltage at that speed?

Is the unit self regulating when charging the battery?

Starter alternators use a standard automotive regulator between the generator and the battery.
They also use a standard automotive relay to engage the heavy load to the starter.
I'm not sure what the max rpm is, but it should be ok at 7000 rpm. On golf carts I think they run in that range.
Hugh Conway's machine has the 23" wheels so he can better comment on the generator speed and output.
On my system the flywheels are 20" and I put a 2.5" serpentine pulley on the starter. The engine runs at 475 rpm so the starter/Gen runs at approx. 3800 rpm. At 3800 it puts out adequate volts for charging but only about 3 amps. Just enough to allow the battery to recover from a start, but not enough to power anything else (except maybe some instrumentation like the Arduino). But that's all I want from it.
Here is my setup as an example...
https://youtu.be/qbcbuygYJdM

If my brain is on the right track I think a nine inch pulley would hamper the motors ability to develop full torque quick enough to not burn.

Really, what RPM is needed to get the Listeroid to fire, say 250 RPM ? That would give you a 3 inch pulley on the electric motor, which I suspect would be much easier for the electric motor to come up to speed.

That also means the electric motor would be revving at 4823 RPM once the Listeroid got up to speed.

scottp,
The pulley is sized so that when the engine is running the motor is not revved up beyond it's synchronous speed.
This is to prevent the motor from becoming a generator and attempting to back-feed the grid in case where the operator does not turn off the power switch fast enough once the Lister is up to speed.

Many members have asked how to add electric start to their listeroids.
Suggestions range from air motors to automotive starters to golf cart starter/generators.

I thought of one very simple method that may work on almost any system
(Unless you are off grid ...  but even that may not be an issue if you have enough battery power and a large enough inverter)

All it requires is an 1800 rpm AC electric motor and a switch. Perhaps 3/4 HP or 1HP.
The 1800 rpm electric motor would be mounted on the same base as the engine with a belt running around the flywheel of the Lister.
For the normal 23" flywheels, the electric motor pulley would be 9.2" diameter to give a 2.5:1 belt ratio (more on that below).
The trick is to not overspeed the electric motor once the Lister starts. This prevents issues of back-feeding the grid.

For example...
This example assume a 6/1 CS style engine running at 650 rpm.
A starter system belt ratio of 2.5 to 1 would spin the Lister flywheel up to 720 rpm if the electric motor were left to run up to full speed unloaded.
Long before that the user would drop the decompression lever and start the engine, then switch off the electric motor.
The motor would spin free on it's bearings with no power flowing to it ... or from it.
With the engine running at 650 rpm, the 2.5:1 belt drive would be spinning the motor at 1625 rpm, well below the motor's normal running speed.

I'm not saying this will work for sure because I have not tried it.
It would be interesting to hear comments from others about the possibility using such a simple system.

food for discussion

veggie

I believe Gary at DES has closed down his business and sold off the inventory.
He was advertising it here many months back.