91 Production model distinctions !

[Steve Swan]

Mark B caught an error on #67.  "No rib" rubber cushion went to 3433, NOT 2157.  Correction complete.

A note to address the keen observation Rick Hahn made of the Owner's Manual calling for a 19mm wrench to remove the oil drain plug in sump pan.  As far as we know, all production drain plugs were 17mm across the hex flats.  It's been confirmed the drain plug on the late pre-production machine was also 17mm across the flats.

[tomcourtney]

Hi Steve, with regard to No 74 the rivited vin tag was for US market only. other markets stayed with N0.73 the no number stick on alloy plate.  Regards Tom

[markb]

Is this the #85 distinction?

Deep, distinct depressions on each side of the near down tubes on 1553.


Smaller dimple on near down tube on the right side on 97.

[markb]

Here's another possible correction to distinction #64.  This pic is from E100 so they were used after E5.

[Wayne]

Here's another possible correction to distinction #64.  This pic is from E100 so they were used after E5.

I must have a major brain cramp. I can't seem to zero in on what we are looking at for this distiction.

64. exhaust spigot flanges, milled radius on each long diagonal side, 1-5 (vin 5-onward, straight, no relief)

[markb]

On later models the four diagonal edges are straight from the screw radius to the big radius.

[kp]

Hi Mark, Yes these are the correct distinctions as identified in the list. Sometimes the distinctions are a little late in being updated but sure will get to em. These are great shots to have as references to identify differences. Can I get your OK to also save these pictures to my own collection for future reference Cheers KP

[markb]

Yes.  Feel free to use anything I post.  That goes for anyone.  If it will help you, help yourself.

[markb]

I compared the front down tubes on 97 and 1553 and found a couple of differences.  There are cutouts on the upper part of the frame where it goes over the down tubes.  The cutout on 1553 is higher and extends to about the middle of the cross tube and there is weld around most of the cutout.


On 97 the upper frame extends down further and the cut is lower and there is no weld.


Here’s a close up on1553.


And on 97.


Also on 97 there are some dimples (from spot welding?) where the upper frame member overlaps the down tube as shown here.


1553 doesn’t have them.  My guess is they welded in the cutout area instead to make it stronger.


I’ll repost some better pictures after I have the frames painted.

[Wayne]

You certainly have an eye for detail Mark! I checked 576. The area you point out is welded although my welds appear to be a bit cleaner. Could just be the pic though.

[Steve Swan]

Here are some more factual findings........

232 has welded bead at the fitting joints and concave dimpled spot welds on the fittings, where the frame tube slides inside fitting ......  

2157 has raised bead and concave dimpled spot welds

4363 has DOES NOT have bead welded joints, and the "spots" are convex dimpled welded areas, not concave dimpled

6147 ditto 4363

Go figure all this........... !?!?!

When i rec'd 232, i compared as much as i could to 4363.  I noted the front down tube weld differences.  Other welded areas, being different, throughout both frames are clearly evident.  The other area that stands out is in the upper shock mount area rear frame secton area.

The frame being a critical component, i am sure there was a welding foreman overseeing the welding, but IT IS INTERESTING that 97 has no welded beads as does 4363 and 6147 (unlike 232.)  232 has concave dimpled spot welds like 97, unlike 4363 and 6147.

All the more minutae that may or may not have meaning and comparing the welds to 97 to 232 to 4363 to 6157, make no real logical sense other than possible changes were made to welding vs not welding the seam and a different technique to making the spot welds, first resulting in concave, then later convex............ ?  

I call it sandcast crazy making............

[markb]

I think I found another distiction.  The early battery box is different.  The one on the left is from 97 and the one on the right is 1553.  Notice that the later one has pins for locating the pieces together, probably to make it easier to weld.


The bend radii are sharper on the early one too and the spot weld patterns are different.  The top on is 97.  I'll repost some better pics after repainting.

[Riccardo]

Mark,

yes, pins for the centering position during the welding fase.

But i see also a different stay for the gummy belt retainer.

[greggo325]

Were all sandcasts fitted with 'no hole' chain adjusters? 

[kmb69]

Yes.