Kohler 4CM21 generator

[Planemech]

Installed in my "new" '83 Rockwood MH. It's putting out 180 volts!! Almost fried my shop vac. Trying to get a manual from Kohler or ASAP. Any suggestions other than the shop?
However I would appreciate any suggestion as to shops that know these gens. I'm near Kalispell, MT (small town) that does have a couple of RV centers.
Generator also takes a while to start off the battery. Starts faster if the truck engine is running. New battery and checked/cleaned all connections. Haven't changed spark plug yet.

[Gary RVRoamer]

Voltage and frequency are driven by the RPMs, so it seems likely your generator is revving to high. Gas gensets usually run at 1825 or 3650 RPMs, depending on the design of the alternator.

[Planemech]

The generator is so old that it is not in the Kohler database. Probably on microfisch in the factory basement! Distrubutor is trying to get a service manual. But they talked me through adjustments anyway. The governor speed control arm has nuts on a shaft for adjusting it's length. They were both backed way off. I adjusted these and was able to bring the rpm down. I then used the Kill-a-watt meter, purchased at the local Home Depot to fine tune. The recommendedinitial setting was at no load - 61 HZ, which gave me about 123 volts. Then turned on loads and adjusted to maintain near 60 HZ with the load on. If I run the airconditioner and microwave it does drop just below 60 HZ but I think that's how it will be.
Got new tires on the front - now we're ready to hit the road!!

[RoyM]

You are pretty much bang on with the engine speed. I worked on a lot of those in a previous life.
My boss had a good thing going with those. The control board was $528.00 CDN in the early 80's. We could not build them because a couple of the components were proprietary to Kohler but what usually failed was a resistor or capacitor. He would sell a refurbished board for 350.00 exchange plus labor, took me 10 minutes to change it. Customer was happy, in and out in under an hour. His bil would then repair the old one for less than 10 bucks in parts and a case of beer.

[Macrosill]

I have a 4.5 CKM21. It as a KT17 twin cylinder motor. I have the Kohler repair manual for the KT17, 19 and 21. If you want it send me a PM with your email address and I will email it to you.

[Planemech]

Thanks for the offer. I've been working with a vendotr and they've semt me four different manuals (including the one you have I balieve) none cover the one I have. I even went direct to Kohler. They gave me 3 publication numbers and the vendor sent those - wrong again. If the manufacturer doesn't have or know what manual I wonder about the rest of their business. One of the problems is that it is a 4CM... apparently a 4.0KW where everything after is a 4.5 KW. It is also driven by a single cyl. engine. Oh well, I pasted together info from each of the manuals and got the job done. "If it was simple anyone could do it."

[Planemech]

Update:
On the way back from Florida to Montana the generator quit. It just bogged down like it was overloaded and then quit and locked up. The starter couldn't turn it. A few days later I tried the starter and it will turn over but makes a clacking noise. Maybe it always did that but I'm leery of trying to start it again. It's winter here now and I'm hooked up at an all-winter RV park so will deal with the generator later. I did think about removing it and taking it home to mess with on weekends.
QUESTION: I know the generator is supposed to shut off at 1/4 tank but it isn't supposed to lock up, is it? I assume I have an engine problem or could there be something in the generator?

[wreng11468]

Hey Brian
I just joined having recently purchased a 1990 National Dolphin 28' RV. I noted you have a manual for the Kohler 4.5ckm21. The generator in my rv is not working at all at the moment. If there is any chance I could get it from you I'd greatly appreciate it. Thanks.
William English

[Macrosill]

William,

Send me your email address via a PM and I will email you the manual. It is in .pdf format.

Welcome aboard and congrats on your new motorhome.

[wreng11468]

Hey Brian
I'm so new at this I can't figure out how to contact you directly nor do I know what a PM is. My email is wreng11468@mac.com and the engine is a KT17. Thanks.
William