19/04/2019
V2.0
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6.2 Basic engine adjustments
WB37 Carburetor adjustments
The most frequent activity is adjusting the idle speed. Membrane carburetors are quite
sensitive to the changes in atmospheric pressure. It means that there are days when the
engine works properly at idle speed, and days when it works unevenly, cuts out or, for
instance, works on too high speed.
Attention: All carburetor adjustments should be performed after warming up
the engine (approximately 2-3 minutes on low and medium speed).
If you notice that it takes too much effort for the engine to start and it does not work evenly
on low speed or if it works unsteadily (e.g. has a tendency to cut out), you should correct
minimum speed settings. It is usually enough to adjust the throttle’s position with a screw
(horizontal screw lifting throttle lever), but in some cases it is necessary to change the
composition of the idle speed mixture.
WB37 carburetor has three screws that can be regulated. These are: throttle positioning
screw, idle speed mixture composition screw (L for low speed) and highspeed mixture
composition screw (H for high speed).
Default mixture composition screws settings for Nitro 200 engine are as follows:
The L screw unscrewed for 1 turn from closed position.
The H screw unscrewed for 1 turn from closed position.
Default mixture composition screws settings for Tornado 280 engine are as
follows:
The L screw unscrewed for 1 turn from closed position.
The H screw unscrewed for 1 turn & 10 minutes from closed position.
