Building a big-bore, 836cc motor for an original Dunstall Honda CB750
Triumph hard-tail chopper
The owner of this bike approached me at the Cycle Expo, complaining of chronically fouled plugs. When I saw the bike, I realized I had a fellow deviant on my hands, and fouled plugs were the least of his problems. But I work on motorcycles, not lifestyles. So I checked the spark. Feeble! I did a little digging and realized that his ignition coils were not impedance-matched to the Boyer electronic ignition unit he had installed. The Boyer likes to see an impedance of 3-4 ohms (the total impedance accross the primaries of the two coils). If you run two 12v coils in series, you get too much impedance. Two 12v coils in parallel, and you get too little impedance. The solution is to run two 6v coils in series. Each has an impedance of about 1.7 ohms on the primary, so Ohm’s Law gives you 3.4 ohms total. Now he has a nice fat blue spark. As for the deeper personal issues this bike raises, I’m afraid I can’t help. Check the battle with the dragon on the tank.
This is a 1973 Mototrans street scrambler that showed up without a spark, among other problems. The history of Mototrans is somewhat obscure. They had an arrangement to make Ducatis in Spain. Rumor has it that when Ducati pulled the plug on this arrangement, and the workers found themselves jobless, they were so mad they burned the plant to the ground. Understandable, perhaps, but unfortunate if you’re looking for spare Mototrans parts. Many of the components on the bike were made by Spanish companies that are now defunct (for example, Telesco forks and Motoplat ignition). Information is hard to come by; this bike required a fair bit of research (thanks to Robb McBee for help finding wiring diagrams). As always, Fred Cousins at Triple O Service in Chicago supplied many answers. I ended up replacing the electronic ignition with conventional points and converting the bike from 6 volts to 12.
1954 Sears/Puch Moped
Someone told me this was the first ever moped. Whatever.
Here is a 1968, low-frame-number Honda CL350 K0, which I sold for $1200.
This project worked out nicely: taking two wrecked Honda CB1s (the reincarnation of the CB400F) and making one good bike. This bike was very fun to ride, and I sold it with reluctance.