81 250 cylinder

[skiracer]

Can someone explain to me why there's a bar that goes across each side of the liner at the bottom of the cylinder.  The 74-79 cylinders don't have that. Doing some quick measurements it appears the two types are otherwise very similar.  Going further, if those bars were removed, would that cylinder work on a 76 bottom end?

1976 250 MC5 Original Owner
1976 Penton 175 XC

[Carl Hill]

That's interesting. I should have looked closer when I had my 81 top end off. Just FYI, my 81 really doesn't feel any faster than my 74. Power is a bit more broad, but 74 has more of a "hit". The 78 I used to ride ( different porting than 74) really felt the strongest.

[skiracer]

Thanks Carl!

quote:Originally posted by Carl Hill

That's interesting. I should have looked closer when I had my 81 top end off. Just FYI, my 81 really doesn't feel any faster than my 74. Power is a bit more broad, but 74 has more of a "hit". The 78 I used to ride ( different porting than 74) really felt the strongest.

1976 250 MC5 Original Owner
1976 Penton 175 XC

[Mike Lenz]

yes  i put an 81 cylinder on a 78. Worked very well. Porting is really the same as a 79 or 80 cylinder though if you want to keep the orig look. Just make sure the old style cylinder has the three finger boost port.