Diameter of the carb where the air filter rubber clamps on?

[Mikep328]

Sorry to ask that question but my storage garage, where the bike stays, is a mile away and I'm hoping to get an answer without having to walk over there.   So the outer diameter of the carb where the air filter rubber attaches is...

 I'm thinking of velocity stacks, despite all the evidence suggesting it's a bad idea.  If someone already knows of a specific stack that fits I'd appreciate the info.

[Multiman]

34.85 and the ridge 35.73mm as a quick measurement

[Mikep328]

Thanks. 

My wife, who rides her own motorcycles was quite impressed when she rode the 400.  She expected it would hardly get out of its own way (she rides a Ducati Diavel) but came back grinning after a quick blast through the gears.  A few minutes ago when I told her I was thinking about putting velocity stacks on it, her response was, "Why?  Do you think it's running too good?"

[K2-K6]

It's an interesting challenge to try and get optimization without airbox.  I feel many start off in the wrong direction with bigger main jets when it should begin with increased idle flow and judge it from there.

The std slides may ultimately need modifications (if you've a spare set) to get a more complete fuel gradient in place without the std box,, filter etc.

This is an relevant thread that could give you a lead http://forums.sohc4.net/index.php?topic=152916.0 if you wanted to more seriously consider a solution.

[Mikep328]

Interesting relevant thread, thanks!  In doing some general curiosity-type searching it seems  that various pilot/main jet sizes and velocity stacks to fit these carbs are not easily available in the UK.  They are in the US which seems odd because the bike is not/was never popular there.  Go figure...

[Jan B]

Expensive but nice stacks:

http://www.steeldragonperformance.com/products_2.html

[Mikep328]

Yes, those are really nice!    Might be a set in my future...

[teenybop1]

Those brass ones look fantastic.

[McCabe-Thiele (Ted)]

On exhausts you had a nice rasp from copper/ brass tail pipes I guess inlets are the same 'sumat' to do with harmonics.

[TrickyMicky]

On exhausts you had a nice rasp from copper/ brass tail pipes I guess inlets are the same 'sumat' to do with harmonics.

. Many moons ago, about 1969/70,  I bought a second hand CB250, the first of the 5 speed models. It was plagued with carb problems so I went to Read Titan in Leytonstone and purchased a pair of Amal concentrics, fitting kit, PLUS!, a nice pair of inlet bell mouths
. . This model Honda was one of the first to be equipped with a fairly loud exhaust as standard, but when the motor started to breathe properly above 7000RPM, those inlet stacks completely drowned out any other sounds. Naughty but Nice!