MDS 1.48 FS Pro Ring, Operating Instructions Manual

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Step 3. Low-Speed Needle Settings
The Pinch Test
You may find it necessary to make low-speed needle adjustments
for your particular application. The low-speed needle is located on
the throttle arm side of the carburetor and requires a small screw-
driver to make adjustments. It’s best to tune the low-speed needle
after setting the high-speed needle.
When you have achieved the proper high-speed setting
(running slightly rich), idle the engine and pinch the fuel line with
your fingers at the fuel inlet of the carburetor. If the engine dies
immediatedly without increasing in rpm, the low setting
in too lean. To correct, back out the low-speed needle 1/2 turn
and repeat the process. When the low-speed needle is adjusted
correctly for idle, the engine rpms should increase 200–300 rpms
when the fuel line is pinched, then the engine should die. If the
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MDS instruction manual 5x6.5 4/28/00 3:09 PM Page 10