6 speed transmission selection

[454MRW]

The topic of 5 sp vs. 6 speed "as delivered" has been discussed with some detail, but never really explained to my knowledge. I have a 1979 KTM MC-80 color fold out that lists in the Technical Specs the 5 or 6 speed transmission CAN BE CHANGED EXTERNALLY and Donny Smith posted Rockets' response to this often asked question:
Mike Lenz is the man to talk to about the 6-speed/5-speed switch. The MC5's that came with 5-speeds actually have a 6-speed transmission with 1st gear blocked out. I believe Mike can tell you how to do this. He is a memeber on this site, look up his name and send him an email.
Rocket
Mike, how about sharing any information you may have so it can be accessed by the entire group. Thanks!

Michael R. Winter
1974 250 Harescrambler
1977 250 MC5 Project
1978 250 MX6  
1979 250 KTM Project
1980 250 MX KTM

[Kip Kern]

Check out a "78" KTM engine shop manual and it will show you the pin in the shift drum!  CIAO

[454MRW]

Kip,
Thanks for the direction! According to the shop manual, the transmission can be changed from 5 to 6 speeds by changing the hexagon head-head dog point screw located just below the countershaft sprocket on the right hand side of the engine case. The 5 speed version is 3mm longer and blocks the use of first gear. The 2 different length screws can be changed externally as long as the transmission is not in first gear or neutral, or damage to the gear shift drum could occur.

Michael R. Winter
1974 250 Harescrambler
1977 250 MC5 Project
1978 250 MX6  
1979 250 KTM Project
1980 250 MX KTM

[wildman]

If you look at the shift drum you will see that there is actually a second nuetral detent notch between 2nd and 3rd gear. The bolt under the countershaft prevents one of the shift forks from sliding over into 1st and makes 2nd the starting gear. I was working on a 1979 175 recently and noticed that very same bolt. What a neat trick!

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125