How to tell the difference between a 125 A B C & D

[skipperclyde]

I have some old Sachs engines without side covers or cylinders.  How do you determine which modles they are?

For my winter project I want to put the tansmission from what I believe is a 5A in a case that I believe is a 6B.  Both  motors have two piece shifters.  

Has anyone done this?  Are the cases the same for all motors?  Can this be done?  Thank in advance for any help.

 

[Doug Wilford]

Skipper;
I am doing the same, as long as the 5 speed has the newer large selector key or two piece selector arm, you should be okay to determine "A" engine (and on all of the Sachs) looking into the crank area the transfer ports are flush with the case inside.  The "B" eng. has a smaller diameter crank shaft and thicker slabs on the crank shaft +  the transfer ports protrude into the crank area.   The "C" engine is a 5speed "B" engine  The "D" engine again the transfer ports protrude into the crank area but leave only enough room for the rod to go up and down,( a very narrow rectangular slot)  Hope this helps.

 

[skipperclyde]

Doug:

I'm not sure what you mean by thicker slabs on the crank shaft.  Do you mean a larger diameter.

The Sachs Factory Repair Manual indicates that 5 speeds were only used in the A & B Motors.

Are all D motors "stuffed"?

Are replacement rod kits the same for all 4 motors?

Thanks for the info.



Edited by - skipperclyde on 09/25/2001  11:10:32 AM

[tlanders]

Doug,

I bought a D engine from Larry Perkins and was dissappointed to find that the cylinder had the cast in intake spigot instead of the bolt on and the case opening was a lot wider than a slot for the con rod. Larry said the case I was looking for was a GS case whatever that is. He did say he replaced the cylinder with a B cylinder. Therefore, from your description of a D engine, the only thing D about mine in the mag side cover with the model number tag on it. Teddy Landers

 

[Doug Wilford]

B engine crank has a smaller diameter,slabs (counter balances) to make the weight almost the same as the A engine they made them thicker.    Your repair manual was probably printed before the C or D engine were made.
To Ted;  I am not so sure the D had a bolt on intake?  I do know we used or had a sleeve bushing on the intake to fit the 30& 32 mm carb with a hose connection.  GS or B would be the same bottom end cases, I think? Starting to push the memory banks, Hee! He!
All these engines have a 54mm stroke, the rod kits are all the same. again I think? I have found the A  uses a shorter pin than the B, we are working on this with the aftermarket rod kit supplier.


Edited by - Doug Wilford on 09/28/2001  5:38:48 PM

[skipperclyde]

I looked at a part manual from EuroRod this evening.  They list the 1960-1970 engine (Sachs) as one part number and the 1970+ as another part number.  It is intresting to note that the 175 Piner has the same rod (part number) as the later Sachs 125.

 

[skipperclyde]

Doug, I have a Sachs cylinder with the bushing you mentioned.  Is there any other identifying marks that would indicate if it is a B or D cylinder