Carbs - Carburetors

inxs

xx
Messages
2,267
Reaction score
118
Points
63
CV Carbs - one of the best how-to manuals ive found for the original carbs

https://www.xs650.com/attachments/carbguide-pdf.248256/

VM Carbs - the same for mikuni roundslide carbs

https://www.xs650.com/attachments/vm34-36-pdf.248257/

Carb Basics - a quickie

https://www.xs650.com/attachments/c-_carb_repair_helpfull_hints-pdf.248258/
old link: http://star.walagata.com/w/sundialmotosport/C._Carb_repair_helpfull_hints.pdf

Carb Theory - a nice basic theory description for carb jetting

https://www.xs650.com/attachments/mikuni-carburetor-operation-and-tuning-pdf.248292/
old linkhttps://www.iwt.com.au/mikunicarb.htm

Mikuni VM - mikuni manual

https://www.xs650.com/attachments/vmmanual-pdf.248291/
old link: http://www.mikuni.com/pdf/vmmanual.pdf

CV tuning...link for low rev and high rev motors

http://www.factorypro.com/tech/carbtun.html

A thread devoted specifically to BS34's as found on the XS650 80-84

http://www.xs650.com/threads/carburettors-from-the-grave.34737

- BS38-34 oem jet settings ... u.s
650carbspecsreducedsizeey7.png


- pilot jets
mikunipilotjetsmoddedam2.gif


- setting the float
XS650_Carb_Float.jpg
 

Attachments

  • carbguide.pdf
    1.4 MB · Views: 460
  • vm34-36.pdf
    94.8 KB · Views: 267
  • C._Carb_repair_helpfull_hints.pdf
    28.4 KB · Views: 197
  • vmmanual.pdf
    594.8 KB · Views: 156
  • Mikuni carburetor operation and tuning.pdf
    173.5 KB · Views: 202
Last edited by a moderator:
Inxs I would love to see all the info you have on your computer! Keep it coming it is much appreciated
 
I have a 1983 Heritage Special (USA) it has an idle sync screw between the carbs. It was backed all the way out. How do I adjust it so I can adjust both carbs idle from the carb on the left side?
 
get vacuum gauges on them, run the bike, turn the screw until they match.

If it's backed right off, the bike must not run very well, and vibrate like crazy.
 
I didn't read all the post but.......Remember the sync screw only raises and lowers the right carb.......... left being controled by the idol stop screw..........

xsjohn
 
What is the point of the plug for the pilot jet. From the illustration in lookslike it prohibits flow? What happens if you don't use the plugs?
 
The BS34 has a closed circuit pilot jet.........the pilot jet feeds through the main jet.... if you leave the black plug off the main jet now becomes the side feet hole under the rubber plug and above the main jet............

You have to think of a ship full of these coming into port with the EPA standing there to test them......just think if they were in control of light aircraft...........

Good carbs but the jets and needles are epa...........everything suffers with that.......

xsjohn
 
THe black plugs can dry out and not fit in snug......and be lost when you dismantle the carbs.......the bowl pushes the black plug tightly to the rim of the tower where they fit.......

It's good to make the timing on these TCI bikes adjustable too........they are a bit advanced......someone's wild idea to turn these wobbly 360 pressed cranks to 7K.....cringe.....and leave the lower rpms suffering..........

xsjohn
 
Back
Top