I bought an RX-8 counterweight and at the same time I bought a '86 to '91 flexplate. (I thought.) Apparently, I have an RX-8 flexplate instead.

Thus, if anyone has a spare flexplate that will fit the RD-1C at a reasonable price, I'd appreciate it.

>>>> Simple way to measure the moment of the flywheel and counterweight <<<

Since the flexplate was wrong, and there are no numbers on any of the parts, I wanted to make sure I had the correct counterweight.

I figured out a simple way to determine if I have the correct counterweight. I bought a lawnmower blade balancer at the corner hardware store. (It is a plastic cone on a spindle.) I put the manual flywheel from my RX-8 engine on the balancer. I put a laboratory scale next to the flywheel. I put a small spirit level on the flywheel center. Using a strip of wood with a pair of screws in it, (one just for balance) I leveled the flywheel by touching the scale with the tip of one of the screws. I twisted the screw in and out until the flywheel was perfectly level. The scale read 5.9 oz, and the screw was 8.5 inches from the center of the flywheel. Thus, the counterweight built into the flywheel had a moment of 50 in-oz.

I then set up the auto counter weight the same way. I got 5.76 oz. With the 8.5 inch distance to center, this worked out to 49 in-oz. Considering the crudeness of the measurement set-up, these numbers are the "same." Thus, I have the correct counterweight.

It looks like they sent me a "matching" RX-8 counterweight and flexplate.






Bill Dube <LED@Killacycle.com>
http://www.killacycle.com/Lights.htm