Question...1978 400 KTM

[firstturn]

What is standard bore for a 1978 KTM 400.  Thnaks.

Ron Carbaugh

[Larry Perkins]

My memory says 82mm with the early 400 in 75 being 81mm.  If I am right do I win a prize, Brother?

Larry P

[firstturn]

Larry,
  You are telling me what I want to hear....I thought it was 81 on the early ones and then it went to 82.  We will see what the experts say.  Thanks for your post.  I hope to see you on the way to the Reunion Ride little Brother.

Ron Carbaugh

[rob w]

Larry's the winner. The 1978 400's bore and stroke is 82 x 68mm. Before that, 400's were 81 x 69mm. The '78's stock piston is the same size as a previous 400's fourth-oversize piston.
Ron, Is this for a cart engine ?

Bob

[Dave Withrow]

Rob,
    Once again, you've beaten me to the punch.  The info I have for the '78 400 is......now get this:
Enduro-355cc bore 81/stroke 69
MC-359cc bore 82/stroke 68

Short answer...........82.
GO PENTON!
Dave Withrow

[firstturn]

Thnaks everyone for taking the time to help an ole Sachs guy.  Rob...this will g in a Kenny Roberts Flat Tracker that is currently a 250.  Thanks again.

Ron Carbaugh

[slvrbrdfxr]

Now I understand why those Texas guys are always so fast !! Looks like they might be disguising 400's in the 250 class. Now why didn't I think of that !! Just kidding Ron !!
Dave McC

[firstturn]

I thought the 250 class went from 250cc to 399cc?? Am I missing something here?  Where is that Larry Perkins....he told me that was how the class was determined.[)]

Ron Carbaugh

[Larry Perkins]

Secrets?  I know nothing.  I see nothing.  Class?  I was late for that.[8D]

Larry P