60 mini kart carburetion, how to calibrate the Dellorto PHPG 18 BS r2523

1 INTRO

As is known, the carburetor has a fundamental role in the performance of an engine. This rule does not even escape the 60 Mini class that uses Dellorto PHBG 18 carburetors. Often, in this class, there are complaints about the difference in performance between carburetors even with the same calibration. Claims that are not entirely unfounded, but for no fault of the carburetor itself (Dellorto guarantees the same quality for all production models), but because of a simple mistake you can stumble into. In fact, there are different types of PHBG 18 carburettors on the market, not only for karts, but also scooters and industrial engines. Version (with the adjustment on the left side) assembled with a needle valve, float valve needles and special floats for the kart is labelled “BS” on the carburetor body and with code “r2523” on the float bowl. Having clarified this, let’s see how it’s possible to fine-tune the “PHPG 18 BS r2523” carburetion to improve performance without, of course, going against the rules.

2 DISASSEMBLY

To get to the internal components you need to disassemble the carburetor. The first thing is to remove the gas valve cover and float bowl to “work” directly on the carburetor. Use a flat screwdriver to remove the anti-swashing cap (component that prevents foam forming in the tank) and the main float valve needle (piece that “sucks in” fuel). Use an 8 mm wrench to unscrew the emulsifier (element that mixes air and mixture) and take off the float, after having freed it by removing the metal supporting pin. Now the carburetor float bowl is clean and you can replace the pieces that allow you to optimise the adjustment of the carburetor.

Remove the gas tank cover and float valve

Remove the anti-swashing cap

Unscrew the emulsifier

Remove the float

3 REPLACING COMPONENTS

The first “replacement” step involves inserting and screwing the drawbore pin (click on the right for details on how to build it) to the sprayer nozzle, so you can remove it with a few hammer blows (it is inserted by interference).
The sprayer nozzle (code 9655.00.28) and emulsifier (code 262 AU) need to be replaced, placing them in their housings, making sure that the facet of the sprayer is on the engine side, otherwise it will not work well. Using the specific drawbore pin, modelled according to the sprayer’s profile so as not to ruin the protruding part the new float must be inserted, forcing it with the hammer until it reaches the carburetor body. At this point, use an 8 mm key (preferably of the tube type) the emulsifier must be screwed into the carburetor body: the new part allows to obtain a better flow of mixture in the carburetor. In order to minimise the harmful effect that the vibrations have on the stability of the fuel level in the tank, it is also necessary to replace the fuel inlet needle (code 11668.00.05).

Insert the drawbore pin and remove the sprayer nozzle

Replace the new emulsifier, on the left

Insert the sprayer with the facet on the engine side

Insert the new nozzle

Screw the emulsifier into the carburetor body

Replace the fuel inlet needle

USE THE CARBURETOR IN THE 60 MINI IN THE BEST POSSIBLE WAY