CDI box and Ignition coil upgrade question  By  dcustriker (Read 2,026 times)

dcstriker,

Welcome to the site!

I'm not familiar with the Naraku parts, but rode a Chinese 150 for more than six years. Indeed, the CDI and coil were parts that from the factory were pretty poor. My original CDI only lasted six months. (And, when they "go bad" they can mimic carb-trouble and other maladies until they "die"...) which will drive you NUTZ!... LOL! I upgraded to one of the inexpensive "red" "New Racing" CDI's from eBay and it was GREAT. Lasted several years, until I got it wet in a car wash... They are NOT waterproof... LOL!

I then replaced it with a "blue" one... It too ran great, and was still on the scooter when I traded up to a Kymco 250. I also early-on, replaced the coil with a Japanese Bando unit. My personal experience with the cheap eBay CDI's and coils was VERY good, and I don't see any real complaints about them.

I also installed an iridium plug. The no-rev-limit CDI, Bando coil and iridium plug was a good combination for many years.

Other simple mods that gave me worthwhile improvements in performance, and general "tunability" included a UNI "sock" air-filter with NO extension between the carb-mouth and filter, the usual richer main carb jet and adjusting of the needle to open faster, AND replacing the stock exhaust header with a full ONE-INCH inside-diameter header. I don't find the mufflers on these to be as restrictive as people think... a free-flowing muffler is good, but, it's the too-small HEADER, choking the engine right at the exhaust port that seems to me to be the real problem. Even "chamfering" the header to "ease" the transition of exhaust from the port to the header helps.

For what it's worth, my Chinese 150 experience was very poor running from the factory. But... replacement of the CDI, coil, plug, air-filter, careful adjusting of the carb, along with a big-diameter header (made that myself...) made the scooter "frisky", VERY reliable, AND easy to tune.

I was completely happy with the little 150 for the last 4 years I rode it. I only went up in displacement to keep up with much faster local traffic on newly-redesigned streets.  I absolutely need a true 65mph cruise, and over 70mph top speed.  My current ride, an old, well-worn Kymco Grandvista 250 seems to be the perfect affordable, reliable and near "bulletproof" ride...  Like a good old family car on 2 wheels.

Chinese scooters are all different, and many mods that work well on one may not work well on an identical model. THAT is probably THE biggest gripe riders have. But when you work out the bugs (and the CDI and coil are among the most common) they are great rides.

Hope this may help,

Leo in Texas