Adjusting The Carburettor - MINSK Repair Manual

When you replace the top lid, the spring and the gate mechanism back to the
main body of the carburettor you will have to slowly slide it back into place
making sure that the long pin fits into the hole at the bottom. If it does not slide in
sweetly then the pin is not in position. With the rectangular carburettor you might
have to squeeze in the
position. Make sure the accelerator cable or the side of the brass gate which has
the semi circle cut from it (rectangular carburettor only) is to the rear of the
carburettor when you slide the parts back on. The round carburettor is easier as
there is a notch which the round solid gate must slide over.
When you screw the carburettor back onto the engine, make sure the gasket
seals between it and the engine are snug, tight and sound.
Never forget that a brand new carburettor will only set you back from US$12-
20 depending on whether it is the square version or the round version so there's no
point giving yourself unnecessary grief travelling around with a bad one.
Adjusting the Carburettor
There are five adjustments that you can make to the internal mechanics of the
carburettor.
(1) Adjusting the Latent Amount of Petrol in the Carburettor
Gravity causes petrol to flow into the carburettor until the float tank in
the carburettor rises high enough to force the stopping pin completely into
the hole where the petrol enters. Between the float and the stopping pin is a
flexible piece of brass. Depending on how you bend this piece of brass will
determine how high the level of petrol is. If you bend the brass up, the level
will be lower. If you bend the brass down, the level will be higher.
flexible brass
connection point
float
tank
petrol
level
NOTE: this diagram is just a representation of how the float tank works
You want the level to be above the bottom of the accelerator jet and just above
the bottom of the idle jet. To get the right level, first allow petrol to enter the
carburettor at its own pace when the bike is off and standing straight up and down.
©Digby Greenhalgh 2000
Minsk Repair Manual
Π
shaped brass gate slightly so that it fits correctly into
stopping
pin
22
petrol enters
here
Level goes up,
float tank goes up,
stopping pin goes
up, petrol intake
eventually blocked