Hi, first time poster here, but what a wealth of information.

I rescued a GS500 from my next door neighbor's garage.  It had been hiding in there since 2008, untouched and all but forgotten. With a little help from a few friends a lot of YouTube videos I was able to clean and rebuild the carbs, change all the hoses, and get it running again. First only the right side, but after cleaning the left side out again, I now have both sides going. Not exactly factory fresh, but as close as I think I can get with the skills and tools that I have on hand.  One of the bugaboos is that it seems to die at about 7,000RPM, like it just isn't getting gas at that range. One of the things I came across was that it could be the needle adjustments, so I opened up the top of the carbs and hoped the needles had a few slots I could put that lock ring on. Not only was there only one slot, when I screwed down the top the hole just crumbled.  I *probably* over torqued it, but just the same, I can't find one anywhere online.  Before I buy one from china or something, does anyone here have a spare I could buy off you?

Also, if you've got any clues to why its sucking wind at 7K, I'd love to hear it. I'm fresh out of ideas at this point.

Thanks so much!

Sorry what - you crumbled the top of the carbs On a bike from what year ?
There are 3 types of tops on US bikes - 89-00, 01-02 and 04-09. Let me know what year the bike is from. Not gonna be cheap, but we can rescue you if you give us some details. No, we are pretty nice people, we wont take your kidney also, just 1 arm and 1 leg. But we need details.
Cool.
Buddha.

Thanks for getting back to me, it's a 1994.

lol I did not crumble the entire carb, I'm strong but not *that* strong. It is the screw hole on diaphragm cover that broke. When you take off the tank and look down on the cabs, it's the black plastic cover with 2 screws. Please don't take my kidney...

The reason it wasn't running over 7K is potentially related to your broken carb top. Vacuum leak is most likely. Slides are not coming up. But it could be a bad diaphragm or other reason, even poor assembly where it's easy enough to get it so the needle binds. I mean, you could have it 100% right with the wrong jets installed and it won't run above 7K, since this is really where it fully switches over from pilot to main jet, so that should help you identify your problem. It could also be low floats, depending if it just basically cuts out above 7k like a rev limiter or whether it will rev fine with no load but dies under load.

I have some broken carb tops, they have the vacuum ports broken off and patched. They are ABS so the patches are likely leaking, need to be redone with plastic weld. Of course you could probably fix your broken one with plastic weld just as well. I've used this stuff with excellent success in the past:

https://shop.advanceautoparts.com/p/permatex-black-plastic-weld-84145/10479442-p

Have you checked eBay? This UK seller has both the right and left diaphragm covers for sell for $30 each shipped.
https://www.ebay.com/itm/183889478817?hash=item2ad0aac4a1:g:2YoAAOSwdAFdL4Si

I did check Ebay and some other places as well, and found some, but I thought if I could help out a person here then I'd try that first.

so, time for an update.  I did all I could for this bike to get it running, and it was running but not great.  So I took it to the shop and had them do all they needed to do to make it as close to perfect as possible.  turns out that the previous owner had tired to mess with the carbs, too, and he screwed the pilot screws in so tight that the heads snapped off.  that was what was causing the fuel flow issues. they were able to pry one out and drill out the other, and now it runs like a top. Phew.