McCulloch 250 - LAMINATION GAP ADJUSTMENT; EXHAUST PORTS AND SPARK ARRESTER CLEANING

LAMINATION GAP ADJUSTMENT
The coil and lamination are mounted on the cylinder beneath the fan
housing. Under normal conditions this unit will not require any
maintenance other than being kept clean. The gap between the two
outer legs of the lamination and the flywheel should be 0,010 inch,
L Remove the four screws attaching the fan housing to the engine
and remove the housing (figure 9) ,
2, Measure the gap with a 0, 010-inch feeler gauge at points
marked "gap" on figure 22 ,
3, Adjustthegap by turning the flywheel until the magnets, set in
the outer rim of the flywheel, are directly beneath the coil. Insert
two 0.010-inch feeler gauges between the two outer lamination legs
and the flywheeL Loos en the lamination mounting screws so the
magnet can pull the lamination onto the feeler gauges. Tighten
the lamination mounting screws, remove the gauges and turn the
wheel several times to make sure that no part of the wheel touches
the lamination legs ,
4,
When replacing the fan housing on the engine, pull the starter
rope slowly so that the starter can engage the crankshaft. Tighten
all four fan housing screws securely.
EXHAUST PORTS AND SPARK ARRESTER
Clogged exhaust ports or spark arrester openin gs will cause loss
of power. If the engine begins to lack powe r, exa min e the ex haust
ports and the spark arrester to see if they nee d cleanin g.
1. Remove the spark arrester.
2. Pull the starter handle slowly until the pis ton cover s the ex-
haust ports.
3, Scrape the dirt from the gasket or rem ove it with a wo oden
scraper (figure 23). Scrape the carbon from the exhaus t p orts .
Do
not use a metal scraper of any kind around the I;; xh aLl::l t por ls , fo r
if the metal scraper slips, it can scratch the pi ston a nd pi:;l()1\ . l'il'l (!:s.
4. Blow away the loose carbon or turn the ch ai n sa w, ~; p ~ \ rk ancsl cr
side down, and shake the carbon particles from the (' X ll ~ LlI il l p urts .
5.
Clean the openings in the spark arrester of a .LL C ~ LJ : I)(lll with a
metal scraper or penknife.
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