Crank Bearing Kits Available - M20 and M25

[KJDonovan]

If anyone is looking for new M20 or M25 bearing kits let me know.  For quite some time I have been attempting to acquire quantities of NOS FAG or STEYR M20 and M25 bearings with brass cages with little success.  

The market is currently flooded with cheap 3rd world (China/India) knockoff's of these I would never put in an engine.  These knockoffs are dimensionally (ID/OD/Thickness) correct, but the inside diameter of the outer race is smaller, balls are much smaller, and the cage is made of very poorly formed plastic.

While there is at least one European supplier with the real goods, his pricing is simply crazy - $180 USD for one M25!  

Anyway, over the past several months I have done some tests using different bearings in both early KTM and Sachs engines and have an approach that works well in both.  Conceptually, this approach is not a new idea and has been discussed here (POG) in the past.  In short it involves using a radial bearing on the primary side and a roller bearing on the stator side to facilitate easy assembly with minimal shimming.

What is different is the style of roller used.  This single row roller has one side of the inner race flanged and the roller cage is machined brass.  Both the are produced by SKF and the RPM rating for the M20 is 15000 and the M25 is 12000.  Based on the tests I have done in Penton engines (both Sachs and KTM) these work as good or better than the original magneto bearings.

I have some of these kits in stock now and will assemble more if anyone is interested.  Pricing is currently as follows and includes USPS Priority Mail shipping in the US.
 
M25 Equivalent Kit - ($108) Includes-
1-   25 X 62 X 17 SKF Deep Groove C3 Radial Bearing
1-   25 X 62 X 17 SKF Cylindrical Roller w/Machined Brass Cage

M20 Equivalent Kit – ($91) Includes-
1-   20 X 52 X 15 SKF Deep Groove C3 Radial Bearing
1-   20 X 52 X 15 SKF Cylindrical Roller w/Machined Brass Cage

Hybrid Kit ($143) Some early Jack Piners had an M20 on one side and M25 on the other – Includes -
1-   25 X 62 X 17 SKF Cylindrical Roller w/Machined Brass Cage
1-   20 X 52 X 15 SKF Cylindrical Roller w/Machined Brass Cage

If anyone is interested, email me – [email protected]

Thanks,

Kevin

[firstturn]

Awesome work Kevin.  Thanks for helping people building these Great Engines.


Ron Carbaugh

[skiracer]

You the man Kevin!  Great work.

1976 250 MC5 Original Owner
1976 Penton 175 XC