Easykart: carburettor, piston, starter… The tricks of the professionals for their management and maintenance

The technical regulations of the Easykart championship also regulate the set-up according to precise parameters. This is why, following the procedures described in this article will also protect you from possible disqualifications during checks by the race inspectors.

The engines used in the Easykart class related to their respective carburettors and pistons, with a particular note on some fundamental measurements and calibrations.

If you have already read (and if you haven't, do so now!) the article ”Expert Advice | Easykart: the 9 basic checks to do on engines, periodically or before buying a used one”, So here is a new episode of the "Advice from the experts" column, created with the technical consultancy of the Birel ART/BMB technical department (engine branch of the Birel ART group). This time we deal with the practical assembly and calibration of the engine, carburetor and starter motor. Revealing tricks the professionals use, during the assembly and routine maintenance phases, to obtain maximum performance and increase the reliability of your Easykart.

By connecting the pump to the mixture inlet of an assembled carburettor, note that by increasing the pressure, through the pump, this will rise up to the maximum opening limit of the needle (for example 0.6 bar), and then go back down quite quickly, towards the sealing point (0.45 bar to give a reference value). Once this point is reached, the pressure continues to drop, but less quickly until reaching the minimum guaranteed seal value (e.g. 0.4 bar). If the pressure retained by the carburettor (for example 0.4 bar) stops its descent, it means that the diaphragms work well, if, otherwise, this continues to drop slowly, it means that the carburettor diaphragms are deteriorated or close to the moment in which an overhaul is required.

To carry out a pressure test it is necessary to have a specific pump with a pressure gauge for the carburettor, although this is an extremely simple operation, it is impossible to carry it out without this tool.

1 What are the fundamental checks to be carried out on Easykart engine carburetors?

All Easykart engines are powered by diaphragm carburettors: the Tillotson 396A, for the 60 cc (EKL), and the Tillotson 397A for the EKJ (100 cc) and EKA (125 cc) engines, while the Tryton HB27 is combined with the HAT (125cc). Checking their correct operation serves to ensure correct delivery and to avoid the occurrence of problems during start-ups, or during carburetion adjustment. The key element of the diaphragm carburettor is the needle inside it, which performs a double task:

regulates, by raising and lowering, the inlet of the mixture into the dosing chamber

keeps the internal pressure of the carburettor constant (for further information, "Technique - The diaphragm carburettor", editor's note).

This is why one of the fundamental checks concerns precisely the control of the value of the carburettor’s internal pressure. There is no exact value to always refer to, but a range, from 0.4 to 0.6 bar, where 0.6 bar is the opening pressure of the needle and 0.4 the closing pressure. However, if in the range from 0.5 to 0.7 bar the carburettor proves to work smoothly, this way of getting around it can also work just as well.

EASYKART: CARBURETTOR, PISTON, STARTER… THE TRICKS OF THE PROFESSIONALS FOR THEIR MANAGEMENT AND MAINTENANCE

1 What are the fundamental checks to be carried out on Easykart engine carburetors?