Crank bearings....

[skiracer]

Since it is about impossible to find multiple piece M25 crank bearings for the KTM motors, has anyone come up with an alternative bearing to use in these motors? Jl

[JP Morgen]

You can use standard one piece bearings, just makes it harder to assemble and disassemble.

[pklinck]

Skiracer,

Talk to Chicago Jerry about this subject since he rebuilds the engines and may have several solutions.

peter klinck

[DKWRACER]

M25 Magneto Bearings, wonder if these will work:
http://www.wuxibearings.com/New_products/Magneto_Bearing_N3048__E15__BO17__L20__M25_274.html
Just a thought, Tom Brosius

[brian kirby]

I've heard lots of explanations of why you need to use those three piece bearings, but none of them ever convinced me. There is absolutely nothing different or special about the KTM engines that they can not use a regular one piece bearing.

Brian

[G Ellis]

Tom I have order these from them. I have been waiting 3 months for them to make it to my house. I now have some coming from the UK now. Waiting for them for a month now. Hope I get some soon, have a lot of money tied up on these bearings. Will have some to sell if I ever get them here.

[DKWRACER]

Good onya Bro...!!!!!!

[Mike Stephenson]

Gary...keep me at the top of that bearings list!  Spring will soon be here.  But fact is, the wait buys me time to get the rest of the work on the bike done.

Mike Stephenson
Atlanta, Michigan
Penton Newbie - thanks to Young Ted!

[joe novak]

I believe the crank bearing design had something to do with axial load in early Sachs engines from the helical cut primary and clutch gears.   If the KTM engines have straight-cut gears, it would not be such a big issue.

[adrian_goold]

I have been using the NJ series of cylindrical roller type bearings, allowing easy removal of cases. I still shim them out to suit the cases with regards to side clearance.

Regards,
Adrian

[t20sl]

I have to agree with Brian.  Regular bearing should work fine.  Joe, I have heard same thing about axial load and helical gears but Honda used helical gears on say a MT250 and still used regular bearings.  Just depends on which college of engineering the guy graduated from who designed the engine, and always a reluctance to change from the previous engineer's design if it worked.  
Ted

[Keith Meatyard]

This is a supplier who carries and stocks M25 and other sizes, that is located in Cleveland, and sells to the public.  They have 100 M25's in stock currently at $ 24 each.  They are no name brand, could be chinese.  Also, I recently took apart several 175 KTM's.  Some have M20 on both journals, some have M20 on one side and M25 on the other.

 http://www.powerdrive.us.com./index.html

Keith Meatyard

[Mike Lenz]

Im not sure but I think Al Buehner said they should be avib at bearing houses under the Fag brand??