Generator Motor Tuneup

[Richard and Rhonda]

My gennie, a 20KW Kohler, powered by a 4TN84TE Yanmar engine, was running very rough and smoking at times. It has always run a little rough and rumbly but since it ran that way since I bought the coach, I thought it was the nature of the beast.

During my adventure of working on the Series 60, I ran the gennie a lot to power the furnace and air compressor for the impact wrenches. It ran rougher and rougher over the last couple of months.

I decided to pull the injectors and set the valves. The tips of the injectors were completely covered in carbon and the injector tube in the head was occluded by carbon deposits. I cleaned the injector tips with a bronze brush, and disassembled the injector nozzles. I squirted a solvent through the tips to make sure none of the holes were boogered up. Then reassembled the injectors with ATF as the lubricant.

It took less than an hour to put the injectors back in and set the valves.

OH MY!!!!! I have a new generator.

It runs much smoother and quieter. No rumbling or stumbling like it used to do. The stumbling would wake me up at night when we were boondocking. It makes sense, the big generators really don't do much more than idle unless we are parked in the sun with all AC's blasting. The idling tends to build up carbon in the diesels.