Mikuni VM36 Carb question

[Velomanx]

Hi,

UK biker here, I've seen a carb for sale on a US website but the company don't seem to know what they are selling and suggested that I join this site and ask for an answer.

Here is the carb I'm after http://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-carburetor-parts-mikuni-36mm-carburetor-mikuni36mm-001-123-sr-xt-tt500.html

What I want to know is if it is a "smoothbore" like an Amal Mk 2 Concentric smoothbore rather than an ordinary Mk 2.

Any of you guys out there familiar with Mikuni carbs.

Incidentally the class I race in doesn't allow flat slide or power jet carbs, so that's why I'm after the Mikuni.

I have an Amal smoothbore but it is to small and the dyno guy says that it is restricting the power output.

Hope that someone knows the correct answer.

 

[Tim]

I don't honestly know what constitutes a carb being a smoothbore or not, but I run Mikuni VM carbs on my BMW R75 (VM32's), XS650 (VM34's) and SR500 (VM36) and like them a lot.

Easy to tune, the jets are all interchangeable, simple to take apart at the side of the road, no o-rings and diaphragms to rot...

What bike are you putting it on? Is it the Yamaha 500 single as mentioned in the Dime City link?

 

[Sonreir]

Smoothbore carb is one where the bore has been machined after the casting rather than purely cast. Almost all carbs are smoothbore these days.

 

[Velomanx]

That's a good way to describe it - thanks.

Yes, the diameter from the airside right through the mixing chamber and through into the head throat is one constant diameter.

On a non-smoothbore the section in the mixing chamber is larger and then narrows off again which causes a disruption which is detrimental to the air flow.

It is going on a Velocette 500 single that I race in the Classic TT in the Isle of Man.

 

[Tim]

There are dimensions for the VM carbs online but I'm very sure the air intake side of a VM36 is much larger than the head side. By your description do you mean the bore right through the entire carb is the same 36mm?

Sent from my LG-D852 using DO THE TON mobile app

 

[cxman]

let me know if you need some help setting that up or with a cable