Technical More Weber information.

[jjacob]

Found this link to an enormous source of information for Weber carburetors.

http://www.webercarburatori.com/?p=handbook

Interesting that in Part 2, Figure 31, the graph says that the best venturi diameter for a single one barrel carb on a 650cc engine is 26mm.

John

 

[Bambino]

John,

Great information. I have a copy of the Weber Factory Tuning Manual (in English) which repeats a lot of that information and has extra chapters and tables on tunable parts, original factory installations, troubleshooting etc. etc. I've attached a couple of pdfs of the manuals. The tuning manual is a 16Mb file and is an old edition - the one I have is the latest edition and it is still available in either English or Italian. It contains a lot more information than the attached pdf.

Out of interest, I visited the old Weber factory a couple of years ago when I was in Bologna. It is now part of the Marelli empire and largely dedicated to office space, but there is a lovely museum with examples of all of their famous carbies as well as lots of old photos of the factory in its heyday, cars, engines and drivers. The two guys who showed me around were retired Engineers, real enthusiasts and full of great stories of their many years with the factory.

Chris

 

[JakeF]

I haven't played much with 4-stroke engines. Don't know if the same rule in 2-stroke motor.
A good example a 2-stroke yamaha rd 350 gave a coulple hourses more with a 28 mm mikuni vs 34 mikuni. So, its not straightforward "the bigger the better" in carbs .
Offcourse it depend of the other motor setup etc..