Standard setting (without tachometer)
To readjust the carburetor, start with the standard setting.
– Carefully screw down both adjusting screws (H and L) until they are against their seats.
Then make the following adjustments:
– Open high speed screw (H) one full turn.
– Open low speed screw (L) one full turn.
If no tachometer is available, do not turn the high speed screw (H) beyond the standard setting to
make the mixture leaner.
Adjusting engine idle speed – Adjust idle speed with a
tachometer. Adjust specified engine speeds within tolerance of +/- 200 rpm.
1 Adjust engine speed with idle speed screw (LA) to 3,300 rpm.
2 Turn low speed screw (L) clockwise or counterclockwise to obtain maximum engine
speed.
If this speed is higher than 3,700 rpm, abort the procedure and start again with step 1.
3. Use the idle speed screw (LA) to set engine speed again to 3,300 rpm.
4. Set the engine speed to 2,800 rpm with the low speed
screw (L). Starting from the standard setting, use the high speed screw (H) to adjust the maximum engine speed to: 14,000 rpm (MS 230, 250)
If the setting is too lean there is a risk of engine damage due to insufficient lubrication and overheating.
Tony, February 2012
