Look at this drive shaft set up...

[ED66677]

btw what is the weight out of the box of that thing? without batt and radio equipment!

[electric]

Thanks for taking the time to explain the battery issue. I usually run pairs of batteries in a series to get the max voltage. I would like to help you with the weight question, but I have it loaded up with equipment already. When I break it down later to put the new motor and esc in it I will see if I can weigh it at that point. It might be awhile. I am going to run it this weekend and see how it does. I have a GPS that I will try to use, but it has been unreliable lately. I do have a the ability to measure peak amps and some other things so I will do that.

[electric]

I have an update. I ran the boat (against my better judgement) in a local pond since I could not get away this weekend to the river. Here are the stats. 113 Amps(Peak), 1325 Watt Power, 41.2 MPH(GPS). I was running the stock hardware with an x440 prop. and two 4800mah 2s Lipo's (25c) for 14.4 volts.

The second run showed 28.8 mph? Maybe I misread the first run? The problem is I can't seem to pull up the top speed number again on the historical data on my Garmin 101 so I cannot recheck it. I am also concerned that given the high algae growth I may of snagged something and been dragging it along.

Now here is the problem. First run I ran a very short time 3 or 4 laps and the solder melted off the Watts Up connection.

Like a dummy, figured its within tolerance (and I am there so why not run it!) so I ran it a second time with the same batteries for 2 -4 minutes I would guess and it died. I fished the boat in and a second solder joint had failed on one of the batteries. Everything was SMOKING hot. All the plastic had melted off all the battery connections and the Lipos's were way too HOT. The motor and the esc were to hot to touch as well. Sorry I have no data, I lost my $%$%$ heat gun.

At this point I am thinking I should just forget this set up and drop in my 10xl with the 120amp HV hydra rather than trying to work on this. I never intended to use the motor and esc that came with it anyway. It is cheaper,(strangely enough) to buy this boat built (299.00) and throw away the motor and esc than it is to buy a built boat that is comparable without the motor.

On a positive note the boat handled great! It was running a bit wet for my taste so I am going to try and move the CG back a bit and make a few adjustments.

Any one who is more knowledgable than me care to comment on the numbers? What would be a reasonable time frame that I should expect to run on 2 4800 MAH Lipos in a series (14.4 volts) with a boat of this size? I am getting the distinct feeling that I need two 4s lipo's run in paralllel for a good run time?? That is going to get a bit pricey....

[electric]

Here are some pics

...

[electric]

Let me see if I am beginning to understand these motors.

The motor it came with is 2756 kv so it should turn about 2756 * 14.4 volts = 39,686 rpm. The amp draw will be high as show by my data it is up in the 120amp range with a x440 prop.

If I put a 10xl in I should see about 1668 * 14.4 = 24,019 rpm and it will also have a lower amp draw. I am guessing in the 60 to 75 amp range.

Thus, my runtime should almost double but my speed will drop off as well.

The interesting thing is if I look up the chart for a Feiga motor they have a 6xl that is the following spec (feigao 540XL: 540 6XL 2,779 RPM / Volt). That means this motor that came with the boat is roughly about equal to a 6xl to 7xl Feigao motor which should draw around 110 amps?



Is this correct?