P.AP. Team RM80, User Manual

Page: 30 / 40

WALBRO CARBURETTOR
This ROS125 engine is fitted with a Walbro 24, the same carburettor as Top80 engine. It could
be necessary to change carburation according to the season —spring/summer and autumn/
winter—, and to the altitude.
It is extremely important for the best engine efficiency and its own life to keep your
carburettor adjustment under the best conditions..
Carburation can be adjusted by means of a screw located on its top area:
The left screw marked with 1 adjusts the flow of petrol in low RPM (range from minimum to half
throttle); it also adjusts, but not as much, in high RPM (range from half to maximum throttle).
Turning left (open) the mixture will enrich and turning right (close) will weaken (PIC. 26).
Adjustment by default is 1 ½ turns out from fully screwed in.. In order to get this you should
open from closed position depending on the situation (altitude, temperature, humidity, and
air density). On hot seasons, it will be necessary to close it a bit more. These adjustments
will be done every one minutes, (scale according to a watch measurement), since it is very
sensitive.
If the low range is very weak, starting will be difficult and accelerating will fade it away. If the
low range is very rich, it will vibrate and will loose some RPM when you will use full throttle.
Besides, the exhaust fumes will be excessive.
Idling adjustment is very important for two reasons:
1. It will allow the engine to work at its best during
the preparation, inflation, and take off phases, so the
start-up system will turn freely, not wearing its parts.
2. You will avoid suffering from an engine cut, just
when you are about to take off or in any other
preparation moment before taking off, when you
should be totally focused.
The right screw marked with 2 is shorter and has a
conic area (PIC. 26B). It adjusts the idling regime
opening choker plate
at is minimum. Adjust it
while engine is hot and
until it reaches 2100 –
2200 RPM. (PIC. 27).
NOTE: Aluminium is the material used for these carburettors, we therefore advise not to
exceed adjustments. Otherwise excessive use of these screws will wear them and will
provoke intolerances and/or other wear.
(Pic. 26)
(Pic. 27)
Ros 125 Engine, Components and Elements. 30
USER MANUAL