• It's time to vote for the bikes you want to see in the 2025 XS650 Calendar! Vote here!

New slide carbs or carb refurb kit?

I live about 6 hours travel from Auckland.
I buy jets and carbs from Mikuni in Aus.
Post a photo of your carbs showing the places where the parts should be. We can then ID the carbs I have some sets here that may have the parts you need.
Hey, these are the only photos I have of the bike and carbs at the moment as the bike is out in the Western Bay of Plenty in my mates garage. I am pretty sure the carbs are Bs38 but I have attached a few bad quality pics for ID. If you wouldn’t mind checking to see if you have any internal circlip or e clip and jets it would be much appreciated. I can’t seem to find the little clips on Mikuni Oz or Mikesxs
 

Attachments

  • IMG_8588.jpeg
    IMG_8588.jpeg
    741.6 KB · Views: 52
  • IMG_8589.png
    IMG_8589.png
    2.9 MB · Views: 53
  • IMG_8587.png
    IMG_8587.png
    2 MB · Views: 45
  • IMG_8586.png
    IMG_8586.png
    1.7 MB · Views: 52
ID chart to identify your bike by the Vin #. Engine and frame had matching #'s from the factory

Differences between models identified. Not so much on the Special after 1980, still to do.

https://www.xs650.com/threads/xs650...workshop-manuals-and-other-information.30569/

If your bike has a drum mag rear wheel it could be either a US 81SH 4M4-000000, (only year the US got a drum Mag), Barrels and rocker cover was black from the factory

Or Canadian 82SJ 5V5-000101 and on, or 83SK 5V5-030101 and on. Engine is blacked out with polished Tappet covers and engine side-covers.

You will need the Carb Guide PDF. Holy grail to tuning the carbs on these bikes
https://www.xs650.com/threads/tentative-carb-id-layout.43392/
 
Last edited:
Hmmm, the plot thickens, lol. This 2nd pic you've posted of the other slide shows a correct type for the '78-'79 carb set. It has sort of a golf tee shaped plastic bit held in by a snap ring to retain the needle .....

'78-'79 Slide.jpg


So, it would seem you have mismatched slides, probably slide needles as well. The needle used in the '78-'79 slide, the 5O2, is longer than the earlier needles because it sits higher in the slide. It has to be longer in order to hang out the bottom roughly the same amount. Here's the BS38 needles compared. As you can see, the '77 and earlier ones are shorter than the '78'79 needle, tapers are different as well .....

BS38Needles.jpg
 
I have attached a photo of the bike, it’s in good condition apart from the carbs. Hard to start but does run! It’s an import from the US or Canada I think. I am pretty sure they are bs38 carbs but no idea what year. I am just going for what my friend told me.
I think you may have a Heritage Special. I see what looks like grommets for lower side covers. BS34 were the original carbs and I like them. Since you’re not in the US, I’m sorry I can’t offer more.
 
Hmmm, the plot thickens, lol. This 2nd pic you've posted of the other slide shows a correct type for the '78-'79 carb set. It has sort of a golf tee shaped plastic bit held in by a snap ring to retain the needle .....

View attachment 256655

So, it would seem you have mismatched slides, probably slide needles as well. The needle used in the '78-'79 slide, the 5O2, is longer than the earlier needles because it sits higher in the slide. It has to be longer in order to hang out the bottom roughly the same amount. Here's the BS38 needles compared. As you can see, the '77 and earlier ones are shorter than the '78'79 needle, tapers are different as well .....

View attachment 256656
I’m overwhelmed by the knowledge and help on here! 🙏🏽 So do you think having mismatched slides is a going to be a problem? I am struggling to find the e clip parts I need online through mikesxs or Mikuni oz
 
It might be. It's not so much the mismatched slides but rather the needles they contain. They're not the same and the tapers differ slightly, along with the diameter of the tip. But, the 4N8 needle from the '74-'75 carbs is a pretty close match to the 5O2 .....

BS38Needles3.jpg


BS38Needles4.jpg


So, you need to check the needles you have and see what they are. If you're lucky, you may have a 4N8 in that older slide already.
 
I have a set of carbs here that look the same type as the ones in post #15.
No idea what year they are off or if they are complete inside they came with a lot of XS parts I bought as a job lot.
CruzinImage does sell some XS carb parts.
From reading it looks like you need a needle E clip and a fuel float valve is this correct?
 
I have a set of carbs here that look the same type as the ones in post #15.
No idea what year they are off or if they are complete inside they came with a lot of XS parts I bought as a job lot.
CruzinImage does sell some XS carb parts.
From reading it looks like you need a needle E clip and a fuel float valve is this correct?

Yes, I need an E clip for sure, which I’m finding hard to find online and fuel float valve I think. I am still a bit confused to be honest. I might have a needle missing too.

Is there a way you could PM me your number, maybe I could buy the set of carbs from you?
 
I will have another look I think I have some carbs that have been split for some reason, will take some photos with the bowls off to help you to see what you need. Will do this on the weekend.
If they have what you need we can go from there.
 
The set that have been split are different to yours.
Here are photos of the carbs showing the parts you said you need. These carbs are in need of a refurbish and parts of the choke mechanism are missing.
20231209_160422.jpg20231209_160429.jpg20231209_160444.jpg20231209_160807.jpg20231209_161444.jpg

The float is there just removed to show valve.
 
Back
Top