1981 GS 650 Carb Compatibility

[wl1150]

Hey all, was just gifted a 650 E as a project and it came without carbs. I've been researching trying to figure out how to replace them and I know it used 4 32mm Mikuni carbs. It is very hard to find a replacement set so I was wondering what my options are in terms of getting carbs that will fit? I don't care at all about originality, just want to get the bike running well without spending an arm and a leg. Any suggestions in terms of compatibility? I think the gs550 carbs are the same, but are there other options? Different brands? New vs old, any option I will consider. Any help would be greatly appreciated. Hoping for some expertise here!
-W

 

[unfocused]

All 16v small bore engines should run the same 32mm Mikuni carbs - internals are the only thing that change - jetting, needles and such. My memory is vague here as I haven dealt much with the 16v engines.

 

[wl1150]

Thanks for the reply! That is helpful info. Much appreciated.

 

[Nessism]

The first gen 550 CV carbs are very similar. The jetting is different. And there may be differences in how the throttle and choke cables work. There are other GS bikes using BS32 carbs, but they won't fit due to differences in the carb spacing.

 

[tom203]

This set looks salvageable…with a proper cleaning…some jetting maybe be different though

https://www.ebay.com/itm/2354743560...RSR0K5ISZu&var=&widget_ver=artemis&media=COPY

 

[Nessism]

This set looks salvageable…with a proper cleaning…some jetting maybe be different though

https://www.ebay.com/itm/2354743560...RSR0K5ISZu&var=&widget_ver=artemis&media=COPY

NO NO NO. That set has a broken float post! NO!

"No visible cracks or damage" says the seller! BS alert!

 

[Nessism]

I've seen worse. The price is right. As long as they aren't all torn up, they are fixable.

https://www.ebay.com/itm/266676695357

 

[Rich82GS750TZ]

NO NO NO. That set has a broken float post! NO!

"No visible cracks or damage" says the seller! BS alert!

Good eye, Ed………

 

[tom203]

“No visible cracks or damage" says the seller! BS alert!“

be gentle, he did say they were for “parts only”….90% complete!
those frosted cards from other seller likely to have hidden surprises.
didn’t someone on here post a link to float post repair? Maybe OP is the creative type!

 

[Ecampolo]

550 carbs use different jets, emulsion tubes and needes. 550 CV's can work but jetting could be complicated, there is a MAJOR difference in the 550 / 650 needles and emulsion tubes, 550 were drasticly more tapper in the needles and a shielded emulsion tube top. If using 550 carbs I'd start with a jet kit from six sigma using 650 as the base carb spec and start on the lean end for mains as when the slide rises on a 550 the 50 / 60 % opening has a 35 to 40% narrower taper, 550 stock main were 92.5 and 650 were 97.5 , pilot were 40 on the 550 nd 42.5 on the 650. My guess dialing in the mid range with 550 carbs will be a pain. 550's were notioriously lean with the CV's, and raising the needles to get into the taper sooner helped dramitically. The 650 makes way more power everywhere and the TDCC has different intake velocity.