Different KB Leg designs.

[Zen]

I have a couple OB legs. My KBs are different then ones I saw in pics. Did the manufacture make different designs through the years? Is there differences in performance when used converting to electric? Do most guys have a preference one over another? The top pic is mine. The bottom pic is one I found on the net.

[siberianhusky]

The first picture is the "original" which may or may not still be available.
The second if from the next generation higher performance versions that had an actual can style muffler that fit into the cutaway.
Many of us cut up the "original" version made up a header and used a pipe on them.
I have one of these home cut ones converted to brushless on my VS1, mine has more material taken away than the factory version.
Aside from losing a bit of weight there will be no performance difference, they are exactly the same in every other way below the cavitation plate.

http://www.mecoa.com/kb/marine/marine_outboard.htm

Here are the current outboards, I have no idea if they are really available

[egneg]

They are not the same! The one I have has a 5/16 Left hand fine threaded lower bushing (for lack of a better term at the moment). The newer versions are not threaded but captured.

[Zen]

I found out years ago about the left handed bushing. The hard way. Anyway, I want to use it on a 25" f1. Instead of using the 3.5 can a 7.5 leg be used. I have a extra one of those from my nitro days also? Or would the extra weight be a factor.

[siberianhusky]

Did some research, for a short time the 8906 version did have a clamp in shaft/bushing, then changed back. I never had one of this version. Can you still get the clamp in shafts? I don't think I've ever seen one.
All the current models are using the standard left hand thread version. Same part #s

[egneg]

As Zen stated earlier I found out the hard way when I tried to order one as a replacement part about 3 or 4 years ago. I haven't checked lately to see if both are offered with different part numbers.

[siberianhusky]

All 3 current 3.5cc and the older ones aside from the 8906 are using part # 57-8901 - prop shaft assembly.
This is straight from the exploded parts diagrams for all 3, cross checked against the parts list.

57-8901

8685

Prop Shaft Assembly

OB

8935 8907 8906

The clamp in version is not even listed under parts, they tell you right at the top of the page you need to buy new case halves.

[Kris Flynn]

clamp style was on the early motors with small skegs. All good outboards use a left handed threads, or the shaft would come loose.

those 2 lowers in the photos above are exactly the same, one has just been machined to suit the newer style can muffler that came on the SS and SX motors.