Carb slides

[Aches n Pains]

How do you tell the difference between a '78/'79 slide and diaphragm and an 80/81?

Thanks,

Doug

[IanDMacDonald]

I believe the diaphragms are all the same: 73mm. I believe it's the needles that differ between the set of years.

[cajun31]

+1

on that Ian. Aches... read through this thread by Mike Hart... http://www.xs11.com/forum/showthread.php?t=867. Fairly good overview of some of the differences he noted on the different years of carbs. I have seen the diaphragms for sale at various different online stores and Ebay and they do not differentiate on model years just state for the XS1100 etc... There are a variety of different types available. If you are in the market for new ones try to get the ones that have the tab on them as they are easier to keep aligned which can make a difference once everything is assembled correctly. There is another thread around here somewhere that discusses that. As Ian stated the earlier carbs had adjustable needles where as the later did not.

[cajun31]

Here is

an old thread that talked about replacement sources http://www.xs11.com/forum/showthread...ight=diaphragm

And here is a listing on Ebay that talks about the alignment issue and the importance of keeping it the same. http://www.ebay.com/itm/BRAND-NEW-4p...3D271378766900

[TopCatGr58]

The diaphragms may be the same, but the slides are different, they are a little bit larger in diameter in the later 80-82 carbs, so you can't swap them into the other years bodies. I don't recall if the place that sells the replacement diaphragms for the earlier model carbs differentiated between the earlier and later models....but I think they did, because of the size of the inner opening that fits around the slide...needs to be a secure snug fit, and so could be loose if the diaphragm were made for the 80-81's and tried to fit them to the 78-79's.

T.C.

[TopCatGr58]

Update,

Just reviewed the JBMindustries site, and there is a difference between the diaphragms from the early years and the later years. The early years seem to have a 77mm diameter of the outer diaphragm groove on the carb body, and the later ones have a 73mm OD of that groove. SO...they are different both in outer fitting size as well as the inner slide.

T.C.

[crazy steve]

TC, IIRC the OEM diaphragms are the same for both carbs, but there's enough difference in the slide bodies that the JBM diaphragms (which have a different design for retaining them) need two styles to fit the early/late. I have swapped the OEM ones (a PITA, but it can be done with patience) with no issues.

As far as being able to tell them apart at a glance, the early slides use a large c-clip to retain the needle assembly (not the adjustment clip, that's different) while the later slides have a flat tin cover held in by two screws.

[Aches n Pains]

Thanks, guys. Really appreciate it. Working on several sets of carbs and didn't mark the slides well enough.

Doug