The Expansion Chamber Online

Frank Korszoloski's RD350 Creation I almost fell off my chair when I did the Internet search "rd 350 Yamaha". I couldn’t believe it! Not only are there other people interested in RDs; they’re fanatic about them just like me! To this point, I didn’t realize there were so many available options for my bike. The fascination of a RD 350 race bike conversion had manifested itself. Through the RD Discussion Form (http://rd.linefeed.com/rd//discuss.html) I learned of Moto Carrera. I called and spoke with Doug Johnson about all the neat stuff he had to offer. It just so happened that he was running a special on a race bike conversion kit. The kit included: clip-ons, Spec II expansion chambers, tapered headset bearings and bronze swing arm bushings, Dunstall rearsets, rear one-up seat, steering damper, headlight bracket, inner fender, front fender and full fairing. I just had to get it! I would call Doug at Moto Carrera quite often for the next 3 ½ years while building my project bike. Moto Carrera offered so much useful insight. Doug certainly had a lot of patience and always made the time for my calls. For that I must say, "Thank You." The dual headlight look came from 55-watt halogen driving lights purchased at Straco Auto parts in Ledgewood, NJ.

I was able to mount them to the headlight bracket (supplied with the kit) by welding longer bolts to the driving light hardware. To avoid overload of the electrical system, I run one light at a time – one high beam, one low beam.

The steering damper is mounted to the lower fork clamp and bolted to the frame through the left side reflector hole. In addition to drilling the lower fork clamp, drilling of the reflector mount hole was required.

I stiffened up the front fork springs by using a piece of 3-inch PVC, which is slightly longer than the metal spacer that you find on top of the original fork spring. I lowered the battery box a few inches by cutting and re-welding it so it didn’t interfere with the new seat.

The Spec II expansion chambers mount directly to the passenger footrest mounts as the directions suggest. I run K&N individual filters despite all the controversy. They work fine once you get the thing jetted correctly. The rear set footrests required a shorter brake pedal and a bent kick-starter, which was supplied by Moto Carrera.

The oil injection system remains intact and utilizes a reservoir mounted above the rear wheel. The tank mounts to a bracket that is welded to the frame. The oil tank was formerly a gas tank from an old weed whacker. It worked out just right: the tank had a vented top and it’s own petcock.

The rear cowl had to be supported from the underside better than the frame tubes allowed. A piece of plywood is bolted to the underside of the seat for rigidity as well as its somewhat shock absorbing characteristic. A piano hinge is welded to the frame, just behind the gas tank to allow the cowl to flip up like the hood of a car. This gives easy access to the battery and oil tank. The seat cushion is covered by in leather and is mounted to the fiberglass with Velcro for easy removal. The rear inner fairing, just in front of the rear wheel, is screwed to the frame tubes using self-tapping sheet metal screws. The taillight is a dual filament enduro type light. It is bolted to a bracket that is welded to the rear of the frame. This bracket also gives support to the rear cowl from underneath. The taillight peeks out from a hole cut in the cowl. The license plate was too big to mount by the taillight, so I made a bracket and bolted it to the lower right shock mount. The tag is illuminated at night by a tiny dashboard type light bulb mounted up under the seat to the frame. The bulb is set to project a beam of light right onto the license plate.

Due to the lower fairing, the kickstand had to be cut off and welded further back on the frame. The lower fairing is mounted to the front frame tubes by ¼ inch threaded rod. The rod is tapped into the frame and held in place with jam nuts. All fairing mounts use stainless steel, rubber backed fender washers and chrome acorn nuts. The front turn signals are dual filament type and make great running lights.

As you can imagine, the detail that went into the creation of this bike is well beyond the scope of this article. I actually spent more time thinking about how I was going to do something than I actually spent doing it. For anyone who might be interested, I’d be happy to go into the specifics. Feel free to contact me at the e-mail address listed at the end of this feature.

This article wouldn’t be complete if I didn’t acknowledge everyone who assisted in the completion of this project. Most importantly, I couldn’t have done all this with out the help of my Dad. Thank you for all your help. Thanks for everything! Matty’s Auto Body of Landing, NJ did paint work. The Yamaha graphics and fading checkerboard were done by Ad-Venture graphics of Succasunna, NJ.

A special thanks to William Povilaitis a great friend, Rich of Manx Cycle in Dover, NJ and Joe of Morris County Cycle in Mine Hill, NJ and of course Doug Johnson of Moto Carrera.

Pictures of the work in progress can be seen at: http://www.angelfire.com/ca5/sotw/frank3.html

1975 RD 350 Yamaha Timing: 1.8 mm btdc Jetting: 190 mains, stock pilots, needle clip in middle position Engine: Stock Frank A. Korszoloski, IV frank.korszoloski@att.net