BS32mm Carbs on a GS1100?

[Guest]

There are quite a few things that are odd about this GS1100E that I am working on. Its supposedly a 1980 model but looks to have a 1983 cylinder head. I've just stripped the carbs for cleaning. I have got some new intake boots but when I checked the fit, they are too loose. I measured the carbs and they are 32mm. WTF? They should be 34mm. Is there any model that had 32mm carbs? Or is that what was on the shelf when this guy built this bike out of left over parts? I am measuring the carbs right aren't I? Diameter of the bore on the engine side?

[hjfisk]

Yes you measure the inside bore on intake side/ engine side. And yes they should be 34mm carbs

[MiketheBike]

While looking into this a little further, I measured the inside diameter of the intake on the cylinder head and it is also 32mm. Its getting to the point where nothing will surprise me so...... what should the intake diameter be for a 1983 GS1100 cylinder head (grafted to a 1980 engine). Or is there some way a 750 or 850G head will fit on this engine? Like I said nothing would surprise me.

[MiketheBike]

Things just got worse. After persisting and rebuilding the first 3 BS32 carbs, I got to the fourth one to find it was a BS34. Yep One 34mm carb ganged up with 3x32mm carbs on the same engine. At this point I am ready to scrapo any idea of using these carbs and go looking for a serviceable or rebuildable set of the correct carbs. From what I can gleen briefly over the internet, it looks like all GS1100 16v models from about 1980 to about 1990 all used the same carb set up. Does anybody know if this is right? If there are that many years that were all the same I have half a chance of picking up a decent used set. I was going to start calling the local wreckers tomorrow to see what is available (in Australia)

[Katarat]

Good luck with that, it took me 3 sets of carbs to get 4 good ones without broken off or ruined screw driver holes in either the pilot jets or mixture screws on my 80 GS1100 that had set for 10 years after being gone thru by a local shop & ruined. Check them over good before buying, I had to get mine from Ebay

[MiketheBike]

O.K. I got a set of '83 carbs for $200. They seem to be mostly there and diaphrams all work. I think these are set up the same as a 1980 model but the jets were bigger (which might be all right too. One thing I noticed straight away was the spacing was very slightly wider but comparing to airbox it looks dead on. Only thing is bottom gang plate is missing and the one off my other set won't fit (obviously due to the spacing). I can probably make one if I can't find the right size.

[MiketheBike]

I have the carbs apart but I just can't budge the pilot air screws. The air screws in my other set were stainless and came out after a bit of work but these ones are brass. After soaking and heating for 2 days, I still can't get them out. It feels like they move just a bit and then jam up tight. It looks like I am going to have to carefully drill them out and the use an Easy out to get the rest. Am I missing something here?