Carburetor Adjustment; Idle Speed Adjustment - Yamaha MOTO-4 1987 Owner's Manual

Never operate the engine with the air filter The carburetor was set at the Yamaha fac-
element removed. This will allow unfiltered tory after many tests. If the settings are
air to enter, causing rapid wear and possible disturbed without having technical know-
engine damage. Additionally, operation ledge, poor engine performance and da-
without the filter element will affect mage may result.
carburetor jetting with subsequent poor
performance and possible engine overheating. Idle speed adjustment
1. Start the engine and warm it up for a
Carburetor adjustment few minutes (normally, 1 or 2 minutes)
The carburetor is a vital part of the engine at approximately 1,000 to 2,000 r/rnin.
and requires very sophisticated adjustment. Occasionally rev the engine to 4,000 to
Most adjusting should be left to a Yamaha 5,000 r/min. The engine is warm when it
dealer who has the professional knowledge quickly responds to the throttle.
and experience to do so. However, the follow-
ing point may be serviced by the owner as
part of his usual maintenance routine.
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