Will VM carb work with CV carb bike

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Docman24

New Member
Hey guys I got a 1981 Suzuki GN400 that is having carb issues. And I have a question about the carb. I would like to just buy a new carb for my bike but the problem is is that it is a mikuni bs36 carb so I know its a CV carb and I have herd people tell me that I need a CV carb the problem is is that I can't find a CV carb for this model. And I have read this guy who built a bobber put of this bike and he used a mikuni 36 VM carb so I am wonder how well these carbs swap. Is it an easy swap? And if so I know my carb is a 36 mm so do I need to use a 36mm VM carb. Any advice on this and what needs to be done to swap cars would be great thanks guys.

Peace
 
I don't see why a bike that originally had CVs would need to keep them. People on here swap VM carbs on to Honda 350s and 360s frequently, plus many other bikes. Sizing will not be the same, hopefully someone who has more carb knowledge can chime in on the details associated with that. As far as easy, you just need a new throttle cable, and make sure the carb will seat properly in your intake boot.
 
Thank you for the reply so far. Would you guys know if I have to do anything extra with a VM carb to switch it from the CV

thanks for the quick responses so far I look forward to more of your advice

Peace guys
 
Hey guys I need some advice someone told me that guys on here swap CV to VM carb and I would like to know how to do this properly. My carb is a mikuni 36bs which is a CV carb and I would like to know how to do this. What size of vm carb is needed and what changes if any I need to make and how I can go about doing this.

Thanks for all your advice guys,
Peace
 
Hey. Can you provide a bit more info for us?

Are you hoping to swap a rack of carbs.. as in 4 of them on some kind of inline 4 engine? If so, you may be able to find a rack of VMs on eBay or something complete with all the hardware.

It would help to have some additional info to help inform your fellow DTTers.

HR
 
Sorry about that. For some reason my pc hadn't updated the thread. My bad.


Sent from my iPhone using Tapatalk
 
As a crude rule of thumb, a CV carb typically flows about 85% of the same size of a slide carb, so a 36mm CV will flow roughly the same as a VM30. That doesn't tell us if 36mm was the right sized CV for your engine to begin with, but it's a good place to start.
 
Are you sure stock is 36mm? I remember them being huge carbs with small bore?
I have the service date but it's on a different computer
32mm VM works fine and is good for around 50bhp (you have little hope of that with a stock motor ;) )
Find the jetting spec for a SP400, as they had CV carb and should wake things up a bit.
Maybe use SP370 slide carb specs if you go with VM
 
I am pretty sure that that is the stock carb. And when I read use SP370 slide carb specs to go with VM do you mean use those exact carb specs for the VM or go to the 85 percent of the SP370 for the size of the VM.
 
GN motor is almost identical to the SP370 and SP400.
The DR's had different cam timing but I think all DR had slide carbs?
If you find the specs it should give you some decent ranges to work with
As supplied, there is not a direct replacement VM carb made for any four stroke motor ( I don't care what anyone says, SUDCO don't import the correct carb although they should have parts to convert it?)
You may have to go through Suzuki dealers to get correct emulsion tube, needle jet and needle though
SP370 and SP400 both hold amazing vertical wheelies, the GN should be able to do the same with correct modifications (they all top out around 90mph)
 
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