1976 125cc question

[Chakka]

I have a question maybe someone can answer. I have 2 1974 frames. I would like to build a 1974 vintage and a 1976 vintage. Would a KTM 1976 125cc motor fit in this frame? They look the same frame to me in pictures with the exeption of the swingarm. If so I will be looking for a 76 swing arm and motor. Otherwise the bikes appear the same. Am i wrong here?
Thanks in advance
Chris

 

[Mike Lenz]

A KTM moter will not fit in a 74 125 sachs frame. A 72 or 73 jackpiner frame would make a nice 125 frame but would still have the short travel. If you want longer travel I would go with a 76 or 77 mc-5 frame.

 

[Dwight Rudder]

Why would anyone want to replace the Sachs 125 with a 1976 KTM 125?  The KTM 125 was the first year model and I know of no one who could keep them running without seizing or breaking engine cases. This engine was a very poor 1st effort for the KTM 125.
Cher'o,
Dwight

7 time ISDT / E medalist
7 time National Enduro Class Champion.