SACHS crankcase half needed HELP!

[penton117]

Hi fellow poggers,

Does anyone have a good right-side Sachs engine case? Not ignition cover but the actual crankcase half. My old one has an M20 bearing that I can't seem to remove and of course it has also been broken from flying chain.

Short of a replacement case-half, what is the sercet to removing the bearing race? Any help, leads, suggestions or new curse words I can use would be appreciated.

 

[OUCWBOY]

Don,
Hate to burst you bubble, but those engine cases are a matched set. You MUST have both left and right.
Donny

[john durrill]

Ok penton 117,
 here is what i have done on stuborn outer races. 1st make sure the wife is not home!
Get an old cookie sheet and set the clean ( no oil or grease on them ) crake cases on it in the oven. set the oven for 350 Deg. get  a slab of wood . 2x12 or 1/2 inch plywood at least 12 inches wide and set it in the clear on the floor. after heating the cases for about 45 min take them out and slam it on the wooden slab( Make sure the alignment dowls are out so the case hits flat) on the wood. If the race does not come out then put it back in and rase the temp 50 degrees , wait20 or so min's and try again. repeat untill the race comes out. a lot of times at 400 it will fall out on the cookie sheet on its own. Doug has some one that can weld the mag cover seal up if you need that done. just drop him a line .
If you put in a different crank or rod kit the inner main bearing has to be re-shimed on the crank. This is important. ask some one for help if you have never done this before.
JOhn D.


 

[desmond197]

Is the temp of 350 deg. too highI was told never heat cases over 300deg. as the cases may warp. This may have been just for Bultacos but I can't remember. Thanks

 

[penton117]

Thanks eveyone for the advice. I have tried the oven @ 350 for about 1 hour. The other two bearings fell out but the outer crank bearing would not move. I tried  smacking it w/ a block of wood - nothing. I tried reaching in w/ a punch and tapping - nothing. I have never had this happen before. Also can someone tell me more about this re-shimming of the inner main bearing? Thanks everyone.

 

[Larry Perkins]

Is this an A or B motor?  I have some used but thrashed motors and I have one set of NOS A cases.

 

[penton117]

Oh yeah this is 1973 "B" motor that I am currently beating on . . . I mean rebuilding.

 

[Kip Kern]

Send the cases to me and I can remove the outer races for shipping cost and a few bucks.  I have a $150 bearing puller that works!  Contact me at [email protected] and I'll be happy to help.  The old "heat em up and slap em on the work bench" doesn't get it!

 

[john durrill]

wow that got folks going :>)
well the heat and slap or tap depending on how stuck the race is has worked for me. we have never found any warpage on the cases the have been heated up that high. we check ours with a straight edge and feeler gauges.
 
 a race puller would be a lot quicker though.
just never had one to use.

 the shimming of the inner races is due to every crank and every set of cases have slightly different dimentions.every rod kit when installed on a crank will not give the same overall width to the surfaces the inner races are seated on. so we have to check the width  of the crank and the distance the main bearings are located in each case half pluss the gasket and add the amount of shimms to each side of the inner race's so we end up with about .002 end play on a 125 crank. Its not hard if you have an accurate depth gauge and measure carefuly. but it would be a good thing to have some one knowledgable do if you have not done it before.
A crank done right will last for years on a 125 Sachs but one done wrong can fail on your first ride and or damage the rest of the motor.
*GRIN*
John D.



Edited by - John Durrill on 07/25/2002  7:44:36 PM

Edited by - John Durrill on 07/25/2002  7:59:31 PM

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