Meet David and his Yamaha RD500LC
David is no ordinary motorcycle enthusiast; he runs an engineering company and is no stranger to large-scale modifications.
His 1985 Yamaha RD500LC has undergone a remarkable transformation, including upgrades such as monoblock Brembo brakes, Öhlins forks,a Deltabox-style frame and an R6 swivel arm.
It's safe to say that this bike no longer looks like its original '85 version. The frame is particularly interesting ᅳ in fact, it is a skin welded to an aluminum box-section frame, the RD version, which was originally exclusive to Japan and possibly Australia.
David took customization to a new level by creating his own exhaust pipe and clamps. To give the engine an extra boost, he turned to his friend Stan Stevens, who created a miracle with the help of the third stage of processing. David already has one RD500, and this new addition is designed for track days and trips in sunny weather. Consequently, the electrical system has been simplified, focusing on ignition, charging and running lights.
This approach helped to cope with the accumulation of heat around the V4 engine, especially when it is located in a deep frame. The streamlined wiring harness was prudently removed away from the hot exhaust pipes. David used a standard setup for the ignition, but took with him a box of spare parts that he purchased online.
After assembling the wiring harness, sparks were noticed when switching on, but a malfunction of the fuel hoses prevented the engine from starting. Undeterred, David solved the fuel problem and tried to start the bike again, but ran into a problem that caused the engine speed to not exceed several revolutions per minute.
Suspecting the CDI unit or, otherwise, the source or pickup coils, he took his well-known good CDI unit from his other bike Using a special adapter, we connected the good CDI to its proprietary wiring harness
Voila!
The engine came to life, sounding as good as ever, thanks to Stan Stevens' expert redesign. If you're dealing with a faulty old two-stroke engine, it might be worth checking out the "Troubleshooting CDI" articles on the Rex Speedshop website. They offer some of the best information about old CDI available anywhere.