MODEL BC FOR 40 HP YAMAHA SERIES
ASSEMBLY INSTRUCTIONS
YAMAHA MODEL 40XMH, 2 CYLINDER, 2 STROKE, 42.9 CU. IN.
2
When the impeller clearance is satisfactory, bump the nut up snug with a wrench. If the ears of the retainer do
not line up with the flats on the nut, spin the nut off, turn the retainer over and tighten the nut again. In one of
these two positions you will have alignment and can fold the ears up against the nut to retain it. The flat in the
retainer is angled to the ears to allow this.
9. Place the intake casing in position with the lower end at the rear and tighten the six ¼-20 fiber lock nuts. No
lockwashers are used. Grease the threads.
10. If your jet drive was ordered for use with a steering tiller handle, see attached page 4, “Shift Cable and Handle
Assembly Instructions attached, #1914
11. If your motor uses remote controls, attach the shift cable and cable anchor bracket to the jet drive. Slide the
bracket all the way forward and lock the bolts. With the shift handle in forward and the reverse gate in forward,
and with the cam roller at the end of the slot, adjust the cable and/or cable anchor position to this condition.
Shift to reverse and back to forward. The roller should be at the end of the cam slot such that the gate cannot be
forcibly rotated toward reverse. Pull on the gate by hand to verify this. If this forward lock condition is no met,
readjust the cable positions.
12. When converting to jet drive, your motor will have to be raised to height shown in diagram on page 3, using a
straight edge under the boat. Test run the boat and then raise or lower the motor 5/16 inch at a time to obtain the
best results. If you raise it too much it will suck air and cavitate, either on start up or when banking on turns.
When cavitating, the motor overspeeds in spurts and shakes considerably in the motor mount. This is not a
normal condition and should be avoided by proper adjustment of motor height on each individual boat. If you
lower it too much you will have excessive drag, therefore mount the motor as high as possible without allowing
cavitation.
The motor has four sets of upper mounting holes. You will use one set to begin with. Mark pencil lines on the
boat transom through the other sets. Then if you wish to go up or down 5/16 inch, you can drill one alternate
set of holes 5/16 inch up or down from the pencil marks. By alternating between these two sets of transom
holes and the four sets of motor holes, the motor can be moved in 5/16 inch increments over almost one inch.
The transom height should be about 21 inches measured vertically from the boat bottom for short shaft motors
and 26 inches for long shaft.
CAUTION
When starting the engine for the first time, watch to see that cooling water comes out of the small hole at the
rear side of engine just below the powerhead. This is to check your assembly of the cooling water pump and its
connections.
