1953 Kohler L600 Propane Powered 3.5KW Generator - Various Projects

I've been working on my new-to-me Kohler L600-powered 3.5Kw generator. It is both hand-crank start and electric start. I much prefer hand cranking because it is just that much more satisfying to me to hand-crank an old engine to life. Only problem was, I couldn't get it to start by hand on propane unless I used a starting aid. That wouldn't do. Nope, not at all.

Fortunately I ran across a photo of a propane mixer on a guy's generator that is the same as mine. Well, almost the same. These next two photos are of a piece from his propane mixer and the same piece out of my mixer:

Notice any differences? I do have the knurled knob for mine but the long protrusion past the threads on his nozzle is conspicuously missing from mine. Hmm, could that possibly be the issue I'm having with difficult starting? Maybe. So I went about making a new nozzle.

Starting with a piece of brass rod, I whittled it down to the dimensions I scaled from the photo and a couple dimensions given on the website where I found the photo.

Center hole being drilled:

Tapered end being cut using the compound rest set at an angle:

Threads being cut:

Side hole drilled:

Here is the finished product:

Below is a video of the nozzle-making process:

On to the next project. The secondary Garretson KN demand regulator on this generator does not have a prime button, which I gather is pretty much a necessity when hand-starting one of these on propane if a starting aid (i.e. starting fluid) is not used, so I decided to add a priming button. I made the push piece from brass, threaded it to accept a nut, and added a spring. The push piece bears on a plastic disc on the internal diaphragm, so it won't harm anything inside the regulator.

Next project was to make a lifting eye. I welded a loop of steel bar to a piece of angle iron and drilled three holes to line up with engine head bolts.

Next project was to replace the selenium rectifier in the control box. I've read on Kohler forums that when selenium rectifiers die, they usually fry the transformer that is connected to them. I bought 25 amp, 1000 volt bridge rectifiers online, paying six bucks for two. I unsoldered the wires from the old rectifier, added 1/4" spade connectors to the wires, and plugged in the new regulator. I left the old regulator in place (the thing with all the vertical plates) just for looks.

The latest project I just completed was a heavy wooden base with casters, so I could roll the generator around in the garage.

Ok, so what about the starting issue I'd been having? Well... When I first got this generator, I took the "QCC1" regulator that I'd bought for my Onan CCK generator and installed it on this one. Unfortunately even after I made the new propane mixer nozzle (first project in this posting), I still couldn't cold-start the generator by hand unless I held the throttle closed a ways, indicating the cold engine was demanding more fuel than the tank regulator could provide (the engine would start fine on the QCC1 regulator when the engine was warm). It was then that I learned that QCC1 regulators have a flow limiting device in them. I ordered a POL-style tank regulator, which doesn't have the same flow limiter as a QCC1. This last video shows how the generator starts by hand when cold with the new POL-style tank regulator. I just need to make some minor mixture adjustments now...

This next photo shows the difference between a QCC1 and a POL fitting. The POL type is older.