It is advisable to arrange the height ol the engine bed so th at shims or thin
packing pieces can be inserted under the engine bearers. It will then be
possible to obtain accurate alignment by removing or increasing the number
ot shims. Alignment should be checked at the beginning ot, and at least once
during each season as it is common tor same cralt to undergo slight changes
in shape according to weather and drying out due to laying up onditions.
Installation of the engine and propeller shaft
It is most important th at the engine shaft and propeller shaft are in accurate
alignment. The Propeller shaft does not need any extra thrust bearing, as the
rear bearing of the engine is capable of taking the thrust. The propeller
shaft system and the engine should be first assem bied approximately in line.
The exact centralization and linîng up is carried out by moving the engine
little by little, after the propeller shaft system has been finnally installed.
When checking the final alignment of the engine, the fixing bolts of the
engine should first be tightened, then remove the screws and the flexible disc
of the coupling. The position of the engine is correct when the coupling
flanges are completely par~llel in alt directions and centralized. The
parallellism of the flanges can be confirmed by means of a fee Ier gauge.
If the distance between the flanges varies in any direction, the engine has
to be moved sufficiently to correct any misalignment. When correct alignment
is achieved reconnect the coupling. Remove spark plug and turn the shaft
by hand. if the shaft rotates freely and evenly the engine/propeller haft
alignment is correct.
Wh en using a stern-tube provided with a rubber sleeve mounted front bearing,
the front erfd of the propeller shaft has to be centralized carefully to the stern
tube, before final checking is made. The centralization is best achieved by
disconnecting the sleeve, sliding the hearing assembly forward and locating
the shaft in the tube with smal! wedges.
Exhaust pipe
Use exhaust piping having an inside bare of 32 mm (11/4)' The exhaust
outlet must be situated weil above the waterline and the exhaust pipe should
slope towards the outlet from a point as high as possible in the craft. The
highest point should be in the farm of a "swan neck" (see h2 fig. 1.)
The exhaust expansion chamber on the engine gives no silencin.g effect and
should added silencing be required a metal silencer of apprOximately 3-4
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