XSGLENN
XS650 Enthusiast
I know ideally I need 34-38mm but would the 32mm version work well if I jet them properly? The reason I'm considering the 32mm is I've got a new pair sitting around that I could use.
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Mikuni vm32's on 1980 xs650
- Thread starter XSGLENN
- Start date
You may have a manifold fitting problem. On the Mikuni website is a VM chart with dimensions of the carbs and matching manifolds. Look at the manifold bolt spacing for the VM34s and VM36s, then compare that with the bolt spacing for the VM32 manifold...
Tomterrific
XS650 Junkie
I don't think the 32mm throats will be too small. I've read the BS38 flows about the same as a 30mm throat so the VM32 might be a very nice running carb once it is jetted right. Smaller throats tend to carburate better at lower rpm so are the prefered size for best running.
TwoMany brings up a greater problem. That may be the deal killer.
Tom
TwoMany brings up a greater problem. That may be the deal killer.
Tom
The spigot OD on the VM32 is 40 mm., same as the VM34. Tom, I don't know where you read that equivalence; the usual correction factor for the venturi obstruction caused by the throttle shaft and plate in the BS38 is 2 mm. at WOT; but right, if the aim is a good utility carb rather than high performance, the VM32's should be an excellent choice. XSGLENN, be aware that you'll probably have to swap out every piece of brass in them.
XSGLENN
XS650 Enthusiast
I might be jumping the gun here, I bought the bike off Ebay and the seller said it runs rough on full throttle. So maybe I could get away with just a good carb cleaning. The bike will be delivered this weedend so I'll know more about the carbs then. What do you guys think of the stock carbs? Are they worth a rebuild or should I upgrade to a better set. I could always pick up a set of the 34mm's and use the 32mm's on my CL450 project.
Depends on which stock carb set you have. Go to the Tech section, follow the link, read the Carb Guide. Just as a note, the VM32 is the favored aftermarket carburetor on British 650 and 750 pushrod twins. When you troubleshoot that full throttle roughness, remember--ignition first.