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Bosch Points Ignition to CDI Conversion?

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Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,738
Location
AMES, IA USA
Is there anyone messing around with the Rotax Bosch Points Ignition to Nippon Denso CDI Conversion or Bosch Points Ignition to Ducati CDI Ignition, or Bosch Points Ignition to this GY6 Scooter Type CDI Ignition?

Old Way to convert Bosch Points Ignition to Nippon CDI was to replace Top Bosch Coil with Top Yellow Nippon CDI Coil off the Old Horse Shoe Stators and the reindex the Flywheel using a cotter pin.

New Way, by RMS Stator for the Old Skidoo/Rotax 250 Type 247 Singles is to use the whole Horse Shoe Type Stator setup and just drill New Mounting Holes to mount the Yellow Coil Level. Those Old Standard Singles are rated at 5500rpm, so don't work on the other High Performace TNT & Blizzards that are rated at Higher 6500rpm, and 7500rpm. IF, they used a Slot Instead of a Single Locating Hole they could probably be made to work. I still have to get me a Rotary Table so I can Mill one of them Stator Plates. RMS is using a different COMBO Coil/CDI Box, looks like a Newer one off maybe an ATV or Scooter, but the Horse Shoe Stator looks the Same as the old Skidoo/Seadoo Horse Shoe Type.

I have never seen anyone Adapt a Newer Ducati or these Cheap GY6 Type CDI Conversion's done to a Rotax.

Bosch Points Coil is mounted at a 45 Degree Angle to the right like in the last Photo. The Horse Shoe Type Coil is mounted Level across the Top as in the photo. The Skidoo/Rotax Stator Plate Bolt Pattern used, is based on a 100mm/101mm 36 Bolt Hole Pattern. So 360/36 = 10 Degrees for Center Line of Stator Plate Studs/Bolt Holes.

Seadoo's and Skidoo's used these same Horse Shoe Type Stators, as did some other Snowmobile Engines. Most CDI Ignition use only (1) Ignition Map, Skidoo/Rotax Nippon use's (2), that is Why they Idle better than Ducati!

Now I'm not an Electronics whiz by any means and I'm mainly just interested in now for what we can do with using these Stock Rotax Bosch (4) Magnet Stock Flywheel without doing any Re-Keying it and just using maybe these Cheap Horse Shoe CDI Stators on ebay. The Seadoo Horse Shoe Type ($32-$45) is way Cheaper than the Skidoo Horse Shoe Type. They may have different Type Connectors on the Wire ends is all, andmaybe different Colors to confuse us. You can use the aftermarket Nippon CDI Box usually ($40-$60) and Nippon Type External Coils($30-$40).

But, if we can find a way to use these real Cheap GY6 CDI parts, like the CDI Box, CDI External Coil, Spark Plug Wire, would be great to keep the Cost down. The GY6 Crank/Flywheel Tapers and Stator Plate used are different Size from Rotax's, as is the GY6 Crank Stokes are Smaller 41.4mm and 57.8mm. Can a Skidoo/Rotax Stator Plate be Designed to use them Parts, Yes.
 

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