BS34SS diaphragm replacement - concerns

For some reason, my 83 GPz 750 seems to have Mikuni BS34SS carburetors rather than the expected BS34 model. As near as I can tell, the difference the two types is that the CV diaphragm diameter is 70mm for the SS version, as opposed to 73mm for the "standard" version. I ordered a replacement set of diaphragms from JBM, and am midway through the replacement process (you're pretty much committed as soon as that first cut is made...).

The thing that I'm concerned about is that there is a large gap because of the difference between the .204" (5.2mm) groove width and the .155"(3.9mm) "tire" thickness. It seems like my groove width is larger than it should be. I've attached a picture showing how large this gap really is - it's bigger than the spacing between the needle circlip positions. The installation instructions and videos out there all seem to show that there really shouldn't be a gap at all. I also can't seem to find any reports of other folks having this issue.

Has anyone dealt with this before? My plan is to finish up all four, and bias the diaphragms towards the lower edge of the groove (which should result in the richest setting), and then hope that they don't ever work loose.

Well, at least it starts and idles properly now. Took about 30 seconds to sync the carbs with my good ole mercury manometer set. Just got stung by a wasp so I think I'm going to call it a night. I went 25 years without getting stung, and now that I'm working on motorcycles again I've been stung twice in the last week. Coincidence?

Find the nest and KILL THE BASTARDS.
Steve

ayeckley wrote: Well, at least it starts and idles properly now. Took about 30 seconds to sync the carbs with my good ole mercury manometer set. Just got stung by a wasp so I think I'm going to call it a night. I went 25 years without getting stung, and now that I'm working on motorcycles again I've been stung twice in the last week. Coincidence?

When I was young, our house was always infested with wasps. I would open the side gate and get my broom and knock the nest down and then run like Jesse Owens out across the yard and down the street..... and not go anywhere near the downed nest for quite a while. :laugh: