Magnum 57 build (part 4)

[James Crewe]

The next task was the fitment of the water pump and its associated plumbing. This kit consisted of the pump, a foam pump mount, some neoprene tubing and numerous cable ties. It also calls for fitment of the water pick that is located on the transom.

There seemed to be no specific position for the water pump mount to go other than that the instructions mention ‘under the carburettor’. Having looked at placing the pump there I decided that it was a little too cramped (very close to the choke knob) and would like to place it elsewhere. This led to a lot of head scratching and another phone call (sorry Tony!).

The long and short of it is this:

The pump can go anywhere

The pump can be at any angle (it will still pump)

IMPORTANT The distance from the pulse pickup (on the inlet (by default)) to the pump must be no greater than 6 inches

WHobbies turns the centre section of the pump around and actually mounts the pump on the stringer using to extended bolts.

With all of the head scratching done I decided to fit the pump and its associated mount further up the hull (past the carb and nearer the fuel tank). This is because I didn’t like the idea of taking the pump apart or drilling the stringer, I also wanted to use the mount. At this position the pulse pickup tube length was 5 inches (perfect!).

I first worked out all of the pipe lengths (other than the pulse) by trial fitting. Then the pulse (5 inch) pipe was connected to the nozzle on the carb (I could not get a cable tie on this as it was too tricky). The other 2 pipes (in & out) were connected to the pump and finally the other end of the pulse pipe was connected. All pipes on the pump were then secured in place by a cable tie.

The position of the pump mount was then finally decided and marked with a pen. I applied some silicone sealant to the bottom of the hull and positioned the mount on top. I the placed the pump into the mount and connected the pipes to the head (routed under the engine) and the water pickup (down the side). This ensured that I could see if any pipe was pushing or pulling against the pump, as it was all ok the pump mount was finally pressed into the hull floor. With a final cable tie applied to the pipe at the head the pump was fitted (phew!).

Finally the water pick-up was fitted with the help of a little silicone sealant to help seal the holes. The depth of the pick-up is a little bit of a mystery, even though the instructions clearly state a depth of 1/16" - 1/8" the pick-up is angled so this makes accurate measurement difficult (Note will up date when known).