Vintage Dirt Bike Q & A

Boy, I could sure use some insight from somebody who has seen one of these optional CDI units for a 1975 CR250M installed. I have the kit but there is no mounting bracket and no extra holes that seem to be home for the CDI box. I'd like to mount is as Mr. Honda intended. As part of that, do the wires run up the back of the motor like a normal points equipped bike, or do they run up the front to the down tube like a later model MT?

Any help is appreciated.

Thanks!
Jon

The ignition box mounts vertically to the tabs behind the steering tube (the tabs used to mount the coil on points
type ignition) with the plug lead facing aft. The coil does not have a mounting frame, instead it is held in place
by two brackets that consist of two curved pieces that lock together at the bottom and are held together at the
top by a bolt. These brackets locate and mount the coil to the small diameter frame tube under the main backbone
as you move aft (nearly centered under the fuel tank). The wire harness is routed the same as the KO Ms.

Hope your kit has these mounting brackets.

dogger

_________________
1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R

Dogger that's great information. Thanks!
I do not have the brackets, but hopefully I'll be able to visualize and make a set. They don't sound that complicated. Maybe somebody will see this and offer to sell me a pair?
Thanks again!
Jon

Jon,

I did some more research and have some additional info and a diagram. The brackets actually bolt to the
coil. While the coil doesn't have a mounting frame like the KOs, it does have mounting holes fore and aft.
The curved sections of the brackets mount on the small backbone and are held tight by the bolts that
mount to the coil.

Here is a picture of the brackets. You can see the design of the locking tabs at the bottom and the bolt holes
where the coil mounts. Parts #5 and 7 have a 5mm nut welded in place for the 5 X 20mm bolts that attach the
coil. If you can't locate a set, it doesn't look like they would be too dificult to fabricate.

Good luck with it.

dogger

[img][/img]

_________________
1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R

Nice picture. This is just they type of obscure piece that warrants checking Honda's stock. Which microfiche did you pull that from? 75 cr250m?

Thanks again!
Jon

The picture is from the '76 M1 but the '75 fiche is the same. I checked most of my usual sources
for availability and came up empty. The only place I didn't check was Western Hills. Another
possibility would be to keep a look out for someone parting out a '76. I would think most of
them came with the CDI and the brackets you need.

Looks like another one of those hard-to-find "obscure parts".

dogger

_________________
1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R