Well I was starting to doubt my own mechanical abilities with the DT250, I was sure that the missing and farting was caused by a faulty electronic ignition system, so I first replaced the coil (made no difference) then the CDI box, and once again, no difference. OEM CDI boxes are NLA for my specific model but one of the guys on the DT pages suggested that I contact “Rex’s Speed shop” in England as they sell their own ignition components.
I did, and discovered that my particular ignition was a “One year only” unit and are known to fcuk up. They don’t carry replacement CDI boxes for my model because the whole ignition system is at fault. Well that explains why my bike was parked in 1988, with only 9000 miles on the odometer.
What made me happy though is that they sell a complete ignition system which also converts my bike to a 12V system and even includes all the bulbs, horn, rec/regulator, etc, and it’s a simple “plug and play” installation without even needing to be timed. Not horribly expensive at 300 English pounds with shipping (a bit over 600 bucks AUD, or around $400 USD) and while I may have been able to convert it to points using the ignition from my ‘78 model “parts bike” it would still be a 6v system with dim lights, which wouldn’t be much fun at 5am when I usually ride to work.
I broke out the plastic and ordered the kit. I could have bought a Motobatt 12v battery from them too, but that would have doubled the shipping price, so I’ll buy one here. While I’m a little peeved that I managed to find the only model DT250 with a known ignition fault, I’m happy that it won’t be long before I’m riding a nice reliable bike. It’s not a heavy bike, but the thought of pushing it home doesn’t appeal.