Dad's 3 HP Evinrude Lightwin
I ran into an unexpected problem mating the crankshaft from my engine to the new powerhead. The crank was binding and wouldn't turn freely. After considering different alternatives, I simply chucked the shaft up in my drill press and used emery cloth to mill a couple thousandths off of the three main journals. This was time consuming. I would turn the shaft a while, measure the journal's diameter, mount it in the crankcase and try it, mill a little more, measure, and try again. It took a number of tries before I finally got it to where it would turn freely. My best guess is that I removed about .002" from the main journals. Then I thought, what about the rod journals. I clamped the shaft in my vice and attached one of the pistons. In the same way, the rod journals were a little too big and the rods would bind. I couldn't use the same technique as with the main journals, so instead I honed the rod bearings. I finally got everything to turn smoothly and installed the crank and pistons in the crankcase.
Now I realize that this isn't a very scientific technique. But my intentions are simply to get this engine running. It will never make it to the river again. At most, it will be for showing to the family and other's who are interested. I figure the tolerances will be close enough to accomplish that.
I cleaned up the points and coils and reassembled the ignition system. It had good spark from both coils. That was a relief. I visited a local marine supplier and ordered a few of the gaskets that I needed and a carburetor kit. It is now March 28, 2005, and it will be several days before the parts come in.
I completely disassembled the carburetor and soaked it in cleaner for several days. The cork float was very brittle and crumbled in my hand when I removed it. The carb kit included a new one. The main jet was stopped up. Other than that, the carb was in pretty good shape.
The parts I had ordered came in and I finally had a little time to work on the motor. I installed the head and exhaust plate. I installed the kit and reassembled the carb. I installed the ignition and double checked the timing using the ohm meter method. I had good spark at both plugs.
At this point, I wanted to see what the little old motor would do. So, I bolted the motor to the lower unit and clamped it onto a 2 X 4 that I clamped in my vice. I dumped a little gas down the throat of the carburetor, wraped a starting rope around the flywheel and pulled. It backfired once. I pulled again. It backfired again. It occurred to me that I might have the spark plug wires reversed so I switched them around. I dumped a little more gas into the carb and pulled the rope. The engine started right up and ran until all of the gas was burned, just a few seconds. I repeated this several times with a big grin on my face.
Next, I rigged up a temporary gas tank. It took a few pulls this time but with a little adjustment of the jets I got it to run. I let it run 15 or 20 seconds, just enough to know that it would run but not long enough for it to get too hot. Though you can't really tell it, it is running in the picture to the left.
The next step will be to remove the power head from the lower unit and paint it. Once that's done I'll start work on the lower unit. I haven't decided yet whether I'll repaint the rest of the motor or just clean it up and leave it barn fresh. It is now April 14, 2005.
All dressed up and no place to go, at least not yet.
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