I tried experimenting with water cooling on this boat. Normally I just wrap a coil around the motor and be done with it but this time I wanted to try something else. I soldered two pieces of brass tubing onto the motor brush holders. This is where most of the heat is generated so I wanted to see if just putting cooling one these would be enough to keep the motor happy. It did not. The motor got so hot that it would cause water drops to sizzle. Looks like I will still need a coil. | 
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| Ok, here is the motor with brush cooling and coil cooling. I found that this is just a 28 turn single wound motor. It is set up with a lot of timing advance which helps explain why it runs so hot and puts out so much power for the number of winds. If this cooling arrangement isn't enough, I will begin backing down the timing. |  |
| To get the water to the brush head tubes, I added a brass tube to the original water pickup located at the tip of the steerable outdrive. I used the largest diameter brass tube I could get away with and drilled the original outdrive hole to match. I then glued it all together with epoxy. The output of the cooling system is simply a 3/16 brass tube CA glued though the hull. Interestingly enough, there were dimples in the hull on the rear transom exactly where I put the input and output pipes. |  |
| I replaced the mechanical speed controller with a home made electronic one that features a BEC (Battery Elimination Circuit) unit. This controller is not only lighter then the original, it also saves weight since a separate battery is no longer required to operate the radio. I built this using a design I found in SE Modelers, a magazine dedicated to electric flight. |  |
| I found that the steerable outdrive pivot was loose and would allow the outdrive to tilt up and down. I used some 3/16 inch brass tubing to make bushings for the outdrive swivel. The tubing I used fit the swivel pin perfectly and only required that I drill out the outdrive to 3/16. The tubing is sold in one foot lengths and is manufactured by a company call Steelworks and can be found at most hardware stores in the USA. This modification helps keep the outdrive at the angle you set it to. |  |
| I'm going to experiment with different propellers. I've found this to be the best modification for increased speed. This is an Octura X442 which will probably be too big for this boat but it's worth a try. After all half the fun in modifying a boat is finding out what works and what does not. To use a different propeller you will probably need an adapter. Most aftermarket propellers are sized for a 3/16 inch shaft while the Super Hawaii comes with a 4mm shaft. ABC hobbies makes an adapter sleeve so that you can use standard 3/16 inch props instead of the 4mm ones. The adapter sleeve can be bought from Horizon Hobby. It's part number is ABC8000 A reader advised me that to save some money, you can find some 3/16 brass tubing at most local hardware stores in the USA that works great. I found the perfect sized 3/16 brass tubing made by a company called Steelworks. It comes in 12 inch sections that just needs to be cut to size. It fit very well on the 4 mm shaft and the props 3/16 hole. It's probably what ABC Hobby uses to make their adapters. One 12 inch tube will make a ton of adapters for a lot less then what I could buy one adapter for. |  |
