Steering but no throttle

[bettaman]

My father recently bought this boat http://www.hobbyking.com/hobbyking/s...dproduct=14552

For $180 all up with battries it was a good deal. The speed is alright too for the price.

We bought a 3s 5000mah as per the wesbite.

We ran it today for about 4 runs up and down the river. On the fourth run the engine just cut out. However we could still steer.

Anyone have any ideas? I felt the ESC and it took about 6 second before it started to feel buring hot. The engine wasnt that hot at all.

[carlcisneros]

sounds like your esc has gone to the happy hunting grounds.

[bettaman]

Sorta what I figured. I was thinking that this would happen but not on the first run!

[bettaman]

Ok put a new turnigy 120amp ESC in and it works great now.... apart from frying the engine in around 3 minutes!

It stopped on a run and smoke came out from the outboard. Brought it in and the outboard is melted at the top. The wires from the motor burnt of all the plastic cover. Im not sure what happened but the motor was very hot for a long time. It seemed to be getting good water flow.

Im also using the battery they recomended. A 3s 5000mah 20c Turnigy.

Now i need some help in find a new motor and also suggestions on what happened to the old motor, just incase im doing something wrong and burn through another one.

Motor size is
Motor: 2858-1400kv Brushless outboard motor

If i can find a motor on HK that would be perferred as when i do the shipping it can all come in at once.

[Fluid]

Often these cheap OB units have poor lubrication of the flex cable which leads to high amp draw. The first thing to do should be to tear it down, clean out the cable and housing, then re-lube with a good quality cable grease.

I see that others had the same problem with the ESC and motor. The motor is not a 540 size but is instead a smaller 280 - not good. Some also think that the stock prop is too big and overheats things.

Sadly, you get what you pay for. To that $180 now has to be added a new ESC and a new motor and maybe a new prop.....



.

[bettaman]

When purchased I thought the ESC would go quickly... The boat is still going to be quite cheap when you consider its only going to be $215 (not including battery) all up with a good motor and ESC.

Got a Genesis and a Pursuit to keep us busy. Would like to get this boat going again... It was pulling some pretty good speed.

[bettaman]

I found this engine on ebay, would this one be suitable?

http://cgi.ebay.com.au/New-RC-EP-Car-boat-Truck-Buggy-2860-Brushless-Motor-/160565301271

I running a single 3s 5000mah 20c turnigy battery with a 120amp turnigy ESC

[m4a1usr]

I found this engine on ebay, would this one be suitable?

http://cgi.ebay.com.au/New-RC-EP-Car-boat-Truck-Buggy-2860-Brushless-Motor-/160565301271

I running a single 3s 5000mah 20c turnigy battery with a 120amp turnigy ESC

I dont think that ebay motor is the right replacement for your application. Too high a kv. Because of the outboards design I would stick with a kv rating approximate to what came stock. Maybe bump up a few hundred kv but I certainly wouldnt go double. Leopard makes a herd of replacement motors that should be a drop in replacements. The LBP2860/3Y with 1840kv might be right about where you want to be but you could go all the way down to a LBP2850/4.5Y at 1600kv and you would still have way more motor then what originally came with that boat.

Since I dont know the design and construction of that outboard you want to stick with, I am recommending conservative choices for you. A higher Kv motor would allow for smaller prob choices but may cause heat/friction issues for the design/construction of that lower. Even a 45mm length Leopard motor in 4 pole will have more power then the stock motor you have. Just some food for thought.

John

[bettaman]

Thanks for that John. Us newbies need all the help we can get.

What would you suggest in a smaller motor? can you get a little larger than a 45mm. Im a bit worried the the cables from the motor wont reach the esc if it sits lower in the outboard.

[m4a1usr]

Thanks for that John. Us newbies need all the help we can get.

What would you suggest in a smaller motor? can you get a little larger than a 45mm. Im a bit worried the the cables from the motor wont reach the esc if it sits lower in the outboard.

I think there are a couple questions you should answer first to be sure. Does the current 2858 motor you are replacing have long lead wires? I have never seen any of the Leopard 28mm motors myself so you need to clarify if a Leopard 28mm x 60mm motor, 28mm x 50mm or the smaller 28mm x 45mm series all have the same wire length. That shouldnt be too hard. The guys selling them on Ebay can give you at least a close answer.

Next your going to have to determine if all those motors I listed above will fit under the out boards cowling you have. I dont doubt the 45mm and the 50mm will certainly fit. Its the 60mm that comes to mind. You are definately not limited to the 60mm is what I'm trying to say. The shorter 45mm can will be more powerful in my mind compared to the 2858 you are going to replace.

If you could disassemble the lower and see its internal construction you might be able to use a higher kv motor by what you see. My worry is that its not designed for 30k plus RPM's. Higher RPM's means you can go down in prop size using the same batts/esc. But you dont want to trash the lower with more friction due to the higher RPM's. I dont race tunnel hulls or know them real well. But the several I have owned and the current one I do have are/have been all setup for an RPM range right between 26k to 30k. Thats not a super fast tunnel range. But you are not asking for a super fast setup so there is no reason you can operate right in the mid to high 20's RPM range and not be satisfied. But just to let you know, none of us want you to put a bigger, more powerfull, higher RPM motor in just to trash the lower and you once again spend more un necessary money.

So the 64 dollar questions are, does the lower drive line look like it can handle 25 to 30k RPM's? Do you have some smaller props? And lastly are you sure the Leopard motors will fit under the cowling? Answer those accurately and then go for it. Since we have been talking I'm leaning now towards the Leopard LBP3650/3Y at 2450kv as my suggestion. At 27k RPM's on a smaller prop you should be right where that boat will come alive. Just my 2 cents.

John