I've been looking for ignition coils suitable for scratch-built CDI so I stopped by a local motorcycle shop and asked if they had anything in the junk bin. The friendly guy behind the counter tossed me a used DENSO 129700 "stick coil". It's a cylinder about 0.75" dia by 3" long and weighs 3.5 oz. I'll wire it up and try it with a Ryobi 31cc.

Anyone have any more technical data on these puppies? Wiring diagram? Coil resistance & inductance? etc.

Thanks, Dick.

Dick,,,, Please keep us posted with your results using the Denso "stick coil". Lots of us are interested ! Antique

Denso 129700 ignition coil is made by Nippon Denso. Used in several makes of motorcycles including Kiwasaki, Yamaha, Bugati and probably others.

Denso 129700-4000 (JO400 10D09)
- 4.7 Ohm primary resistance
- 17.4 kOhm secondary resistance

New coil prices are in the $40-$50 range. It still looks as if the best deal is the coil from CH.

Your right CH is still the best deal, their coil is well proven. However, the question remains, Does the DENSO coil work ? Tinkerers the world over need to know !

Hi
Yes , it work
I bought a new TEC coil , made in taiwan,original replacement for Honda TRansalp 600 and I blieve Honda XR 250 and Honda XR 600.
I am tested in the bench, more than 6 hours, 4 hours non interrupted , simulating the hall effect pulses at more than 4000 rpm and no problems, with a new plug.
The circuitry can drive the coil more than 9000 rpm .
Other new coil flew without problems with a weedeater 18 cc ( other TEC )
Other coil , old recycled TEC, but made in japan work well.
No problems with noise, wound a recycled copper braid from a RG213 coax cable over the high voltage lead and work.
Have good luck
Jose