7
Improper riding of the scooter merely makes it draw too much current. My motors
are set to 57 pounds thrust with a static draw of 16 amps (that is what the burn
times are based on and the battery condition tests (see the WKPP page for burn
testing details). If you are a good diver, you should draw a lot less than 16 amps.
Speed adjustments allow the team to all move together.
Salt Water Diving
Any scooter used in salt water needs to be rinsed in fresh water afterwards. Don't
let it sit, as the salt water will leave salt crystals which will then react with the
metal parts and get into the surface of the motor seal. The way a seal works is by
a molecule layer of water across its face, not because the material has some
magic properties. We use ceramic seals which will not rust, but will be scored if
left with salt on them or around them. To break in these seals and start the
process, we use a drop of motor oil, but once the scooter is put together, it is not
a good idea to disturb this device.
A rinse in fresh water after diving, followed by a spray of CRC or WD40 around
the area of the seal, will do a lot to prevent any problems. You do not have to
take the props and clutch off, merely use the little tube that comes with these
cans to spray under the clutch and into that area. The idea is to prevent the cone
around the seal from reacting with the salt and eating away. Eventually this
process will leave the seal unable to hold at its edges, even if the two seal plates
are not damaged. Then the whole motor cone has to be replaced, which is
extremely time consuming.
An easy way to rinse a scooter is to put it in a fill bin and run it a few seconds
(with the pitch turned down). You can also use a hose and force water in under
the clutch.
Most of the snap rings are stainless steel, but even that will rust out and let the
seal spring loose, which will push back the clutch plate from the shear pin and
allow the whole prop assembly to unscrew. Once in a while that ring needs to be
replaced. It is just under the clutch plate. The snap ring under the seal is hard
steel. That ring needs to be in place or the shaft will have play in it, causing the
seal to leak when you first put the scooter in the water. There should be no play
in your shaft; if there is, that ring needs to be replaced, which means removing
the seal all the way. The bottom part comes out with an O-ring pick - this does
not hurt it at all. Check your prop set before putting the scooter in the water and
push the whole thing inward to be sure the seal is shut. Otherwise they will leak a
little when you first put them in before the pressure closes the seal. That is where
all the leaks actually happen - right at the surface when you first put them in the
water.
Gavin Scooter User’s Manual and FAQ (
George Irvine 2002)
