Differences in carburetor insulator bands and airbox tube bands

[markb]

I thought this was discussed elsewhere already but I couldn't find the thread.  Sorry for rehashing if that's the case.

The two part numbers I'm referring to are the 8 carburetor insulator bands #17255-300-000 and the 4 airbox bands #17255-230-000.  I seem to recall that there was a discussion about the finish being different.  My recollection is that the -230- bands were likely zinc plated and the -300- bands were shinier, not full chrome but maybe just nickel/chrome.  I have tried to find some NOS -300- bands but they are non-existent.  I have found -230- bands and the newer ones are black.  I also found some old NOS -230- bands that were in the original sealed bags and to add to the confusion they had different plating.  One looked like zinc, almost yellow, and the other looked like the chrome described above.

My main question is, are there differences besides the finish?  It appears that the -230- band supersedes the -300-.  So maybe the -230- was slightly larger but works in both places?  Or there were two suppliers and one was eliminated?  I looked through mine and couldn't see any difference in length but the ends have a slightly different shape.  I have about twice as many as one kind over the other.  If I had to guess I would say that is the carb band.  Does anyone have pictures showing differences between the bands?  I'll try to get around to posting pics of the different ends.

If my memory is incorrect on the finish please set me straight.

Mark

[Wayne]

http://cb750sandcastonly.com/smf_forum/index.php?topic=687.0

[markb]

Doh!    I couldn't find it even in a thread I started. 
Anyway, it looks like I was correct on the finish but there wasn't any discussion about physical differences.

[DW69K0]

Mark,
Attached is a picture from my unmolested Sandcast that shows the finishes from the factory on the carburetor bands. The eight bands connecting the engine to the carbs are chrome but not real highly polished and the bands connecting the air intakes are zink plated IMHO.
Hope this helps,
Duane

[markb]

Yes.  It all helps, the more info the better.  I took a look at some of the old bands I have.  Unfortunately at the time I took them off I didn’t realize they were different and didn’t pay attention to where they came from.  Besides the finish there are different physical differences.  I found at least three differences.  In the pic below the center one has a hex nut for the clamp screw and the other two have square nuts.  The ends (bottom edge in this pic) are different.  Hard to see but the left one has a slight arc on the edge.  The center one is straight and the right one has radiuses on each corner.  I have more of the radiused ones than the other two.  Also the width of the clamping ends are slightly narrower on the center one.  Duane, it looks like the ones in your pic have the radiuses in the corners.


In the other view the bands are shown in the same position left to right.  The end pieces that are welded on to the bands are different.  The left one is distinctly narrower than the other two.  Will anyone who has an example where they are certain the original bands are in place and have never been changed, take a look and see if they match any of these characteristics?  

 

[Steve Swan]

Thanks Mark, for that.  i knew there were differences when i was restoring my bikes 10 years ago, i kept the 8 clamps separate from the 4 clamps, but, there's no way i could ever remember the distinctions between the 2 types.

[DW69K0]

Mark,
You are correct, mine have the corner radius and the bike is in amazing original condition. You can see from the picture that the clamps are installed incorrectly, as they should be reversed and pointed down, probably done when carburetors were cleaned. These are 28 mm carbs with the two hole air boxes that have reliefs and so I am sure they are correct clamps installed at the factory.
Best,
Duane

[DW69K0]

Here is a photo of VIN 1095, which is off our site -
DW

[markb]

Duane, can you see if the clamps have square nuts or hex nuts on both the carb and airbox clamps?

[DW69K0]

Mark,
Attached is the photo of the chrome style clamp. the carburetor to air intake have a totally different clamp style. I will post the zink plated clamp in a different post.
DW

[DW69K0]

Here is the zink plated air intake boot clamp style. I flipped it around and upright for the photo.
DW

[markb]

Excellent.  I checked out the clamps on my early diecast (12xxx) last night to see what was there.  I have both hex nut and square nut versions but they are random in the two locations.  When I put it back together I didn't know they were different and didn't pay attention to what went where.  However the significant thing is that there are 8 square nut and 4 hex nut bands.  These are the original bands.  I owned this bike since 1975 and bought it from the original owner.  It's a 11/69 build so I would say it's possible that it was configured the same as the sandcasts.  So it could be that another difference between the two part numbers is the type of nut with the square nut being the carb insulator band and the hex nut being the airbox rubber band.  Can anyone else verify that?

[Steve Swan]

ya know, fwiw, i looked at all these distinctions in past years, but can't remember s--t and didn't write anything down.  but what you are noting as distinctions trips the "sounds like what i remember" button in my brain. 

just now looked at 232 and 2157, fwiw, each bike has 4 square nuts on airbox and 8 hex nuts on manifold tubes.

[markb]

So just the opposite?    I give up. 

[Steve Swan]

oh gosh.  i apologize for the confusion i'm creating !

4 hex on airbox.  8 square on manifolds.

checked the low mileage K1 i have.  same, except all 12 clamps are bzp.

and the K1 has a Bridgestone, High Speed F2 front tire.  this bike has just over 7k miles, so i am suggesting the F2 may be the original tire.