Stihl 064 - 6. REWIND STARTER; 6.1 Routine Maintenance

STIHL 064, 066 41
4.6 Leakage Testing the 4.6.1 Preparations
Crankcase
Top:
Carburetor and crankcase tester Top:
1106 850 2905 Muffler upper casing mounting screws
Bottom: Bottom:
Vacuum pump 0000 850 3500 Muffler lower casin
g
mountin
g
screws
Defective oil seals and gaskets or Moreover, the transition from idle - Take out the muffler upper cas
cracks in castings are the usual speed to part or full throttle is not ing mounting screws and remove
causes of leaks. Such faults allow smooth. the upper casing.
supplementary air to enter the
engine and thus upset the fuel-air The crankcase can be checked - Slacken off the muffler lower cas-
mixture. accurately for leaks with the car- ing mounting screws about half
buretor and crankcase tester and way.
This makes adjustment of the the vacuum pump.
prescribed idle speed difficult, if
not impossible.