Sachs crackshaft info needed

Started by thrownchain, November 25, 2007, 09:27:02 PM

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thrownchain

I've got a couple of motors apart and noticed I have two different size flywheels. Most are a smaller dia, but one is slighter larger,any reason?? Is it a "trials" motor? All are six speed motors.Any help?  thx

Doug Wilford

a FLYWHEEL is part of the ignition system I think you are refering to the slabs of the crankshaft which there are two "A" and "B" "A' has a larger diameter but thinner thickness, "B" is a smaller diameter but the slabs are thicker, the cases must match the sizes of the crank slabs.   "A" engines were the early engines 68-69-70  Late 69 was the beginning of the "B" engine.
Have Fun!

Rain Man

Doug, have you ever thought about writing a small book  on the repair and rebuild of the Sachs motors ??
  I dont remember all this stuff !! Some of it; maybe. All of it,[?]
 the details will getcha everytime ;)


Raymond
 Down East Pentons
Raymond
 Down East Pentons

thrownchain

OK I'll call them the crank wheels. The motor came out of a 72 Penton six day bike I got off E bay. 6 speed tranny, the wheels are 108 mm while the ones in the other motors I have apart are out of DKWs, the motors are the same, except the wheels are 90 mm. The measurement is across the widest part of the wheels. Going to make getting gaskets fun, as the cases are forged for the wheels. All other gaskets are the same, just the one between the case halves. Can't see any other differences. thx

brian kirby

You have a 6a engine which had the larger crank weights. The 6b has smaller crank weights and has the cases cast to follow the smaller size.

Brian

'72 Six Day (on loan from Ernie P.)
Brian

john durrill

thrownchain,
 Follow this link and look in A and B engine differences folder.
The A crank has larger diameter flywheels like Doug's post describes
Can you see the differences between the crank and engine cases from the Photos posted? If no i will try and get more and better pictures for you.
 http://www.flickr.com/photos/12809785@N06/
 Hope this is some help. The first 3 Sachs engine CMF Pentons we got in 72 were 6A's one was a 100 and the other 2 were 125's all had magnetos instead of motoplats.
John D.

thrownchain

Thank you sir, it helps to see pics. It's also nice to see "clean" parts. Even after I clean up what I've got, they don't look that nice. I'll have to keep the differences in mind when I order parts.  thx