Sachs Engine I.D.

[Darvin Jahnke]

Is there a way to determine the model of a sachs engine if the tag is missing? Bore size will tell the ccs but beyond that? I suppose a guy could find neutral and see if it is a 5 or 6 speed. I was just wondering if there are any other id marks or features that will tell. Thanks

[OUCWBOY]

One way to tell the difference between a B motor and a D motor is the number of fins on the cylinder. A & B motors have 7 fins and the D motor has 6 that are spaced a bit further apart.  Also, the D motor does not have the spigot for a slide on carb, it had a bolt on manifold. As far as the difference between a 100 and 125 is really only the bore. Std for a 100 is 48mm and the 125 is 54mm The heads have different parts numbers, usually cast on the underside of the head. If it had the tag, it really doesn't mean anything as the tag is attached to the side case, which we all know are easy to change, as well as someone could have replaced the piston, cylinder and head.

Donny Smith
Paragould, AR

[gooddirt]

An  -A- motor you can see the whole Crank halves.

[joe novak]

Great and accurate info posted by "gooddirt" and "OUCHBOY".  Never rely on the info of the sprocket side tag.   If you remove the clutch cover, you can view the shifter mechanism which should relate to the number of transmission speeds (remember to count the true neutral notch).   Good question!  Because many of the Sachs parts are interchangeable, it can be a challenge at times.  joe   fyi. 100cc cylinders are easy to identify when removed because of the front and rear slots in the lower sleeve for rod clearance.

[Don Roth]

I believe the 'B' has the larger (in diameter) front mounts and
also the magneto wiring access hole is different, the 'A' has a u-shaped cutaway and the 'B is just a hole.

[Dale Fisher]

I believe the cylinder difference(s) were discussed in the tech section of the Winter newsletter.  

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Dale Fisher
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1970 Six-Day 125
1971 Six-Day 125 (Dave Fisher's)
1973 Jackpiner 175
1974 Berkshire 100
And some silly other bikes...