How do you adjust a carburetor? Nozzle sets for DellOrto Mikuni and Keihin

Adjust the carburetor with the precision part carburetor nozzle

For the Setting the ignition there are now excellent tools like that buzzwangle or Walthat allow a precise ignition position and make work extremely easy. Adjusting the carburetor, on the other hand, is the most difficult part of tuning a scooter for many.

If setting the air mixture and the idle gas is still child's play, it becomes more time-consuming to determine the correct nozzle sizes for the individual engine setup. Here, the carburetor needles, nozzle assembly, main and auxiliary nozzles interact and, perfectly coordinated, result in a clean setup.

If you choose a nozzle that is too small, the engine runs too lean, gets too hot and major damage is inevitable.
Too large a nozzle and too rich adjustment can lead to engine damage. Quite apart from the fact that the capacity of the engine is not exhausted and working time and money for elaborate tuning literally fizzle out.

How do you adjust a carburetor?

As an example for a Lambretta, we have prepared the PDF, which is described in detail and illustrated, with suggestions for the setup for you.
Free download here: Lambretta carb jetting by Scooter Center

From the tutorial - when does which nozzle come into play?

Precision product carburetor nozzle

DellOrto nozzles, for example, are stamped with a number that refers to the size of the hole. A 100 nozzle has a diameter of 1 mm, a 115 nozzle is 1,15 mm (!!) only a tiny amount 0,15 mm larger!

If you want to be on the safe side here and rely on high-precision tuning, we recommend using the nozzles bgm PRO or KMT to fall back on. These nozzle sets are characterized by

• high-precision drilling
• minimal tolerances
• meticulously precise graduation of the nozzle sizes
• easy to read numbers
• high quality of workmanship and material
• Quality control
• including storage box

 

Precision nozzles from bgm PRO or KMT for clean engine tuning

You have invested a lot of love, time and money in your engine tuning. But the most expensive and complex tuning, with the best components, is of little value if the engine does not run smoothly or if a poorly adjusted carburetor does not allow optimal combustion. In order to be able to tune the engine correctly, high-precision carburetor nozzles are a very important prerequisite and make adjustment a lot easier!

 

Nozzle sets from bgm PRO

Nozzle sets from KMT

 

Quality assurance bgm PRO carburetor nozzles tested under the microscope

We had the new bgm PRO carburetor nozzles checked at an institute. Here is a glimpse into a 118 nozzle, with a dimension of 1,1779 mm, the bore is in the green area with a deviation of only a thousandth of a millimeter and is therefore OK!