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I read Johnc's thread about a leopard that did not run after he bought it. And I PMed him to see if I could buy the motor from him cause I use a Leopard 4074 in my P-mono, it's the very first FE motor that I ever bought, and I thought it would be good to have a spare. I burned mine up at the Michigan nats because the boat took a dunk but came back up and went on to get within 30 feet of the finish line......and stopped
The batteries slid forward about three inches cause I didn't have them secured very well.
I have won a lot of races with that old Leopard so when I got back home, I set forth to rewind it and get it back into the action. I was able to put a good bit more wire into it as the Leopards are not very full from the factory. And of course I used good 200*C wire, so the motor can take a lot more abuse now and still come out ok. Had I done this before going up to that race, it would have made that finish line and then some, and still been ok, just hotter than usual. And to prove this to myself, at our recent Atlanta Model Boaters Grand Prix race this past July, I had the recently rewound Leopard back in the boat and running as good as usual. I normally run an ABC 1714-17-45 and that's fast enough to get me into trouble when the water gets rough. It will pull a 1715 but does get a little warmer, so I prop down to be safe and finish the race. But on the last heat of our race, I decided to see if the rewind was actually any benefit I was out of the running cause of a mistake or three anyway. So I put an ABC 1814-17-45 on it, HO LEE SHIP that turned it into a rocket! I don't know how hot it might have gotten cause I only made it 4 1/2 laps before I subbed it by being to aggressive, but man it was fun. I was all over the leader (Doug Smock) and he has recently motored up with a BIG TP replacing his old 1515 Neu.
So when John's post came up I figured this might be a good chance to get a spare. John's is an 82mm long version, vs my 74mm, but the extra length wont hurt anything in my boat, And the KVs are the same so if I did swap motors, I wont have to change props if I don't want to.
John agreed to sell me the motor cheap enough, cause it's just a paper weight to him now, I hope he didn't pay to much for it when he bought it. I got it in last evening and tore right into it and found the short right away Where the leg wire bundles wrap over each other on the rear of the motor. There was a little bit of black residue and two or three blown wires. And on the PTO side there was also a tiny spot with just one or two wires blown into. But what happens, when this happens, is that when a wire does get hot enough to burn the insulation off, then it also usually burns the wires that are pressing tightly up against it. And if those wires are on another leg, POOF! Now when the ESC is sending a positive signal on that leg, it runs into the short and either gets in the leg that has the negative side on it, or get into the OFF leg which is supposed to be sending back EMF the the ESC to tell it where the rotor is positioned. So either way the poor ESC can't figure out what to do, so you get the shuttering/ single phasing.
I'll post a few pictures as I go to try and show what's going on.
The batteries slid forward about three inches cause I didn't have them secured very well.I have won a lot of races with that old Leopard so when I got back home, I set forth to rewind it and get it back into the action. I was able to put a good bit more wire into it as the Leopards are not very full from the factory. And of course I used good 200*C wire, so the motor can take a lot more abuse now and still come out ok. Had I done this before going up to that race, it would have made that finish line and then some, and still been ok, just hotter than usual. And to prove this to myself, at our recent Atlanta Model Boaters Grand Prix race this past July, I had the recently rewound Leopard back in the boat and running as good as usual. I normally run an ABC 1714-17-45 and that's fast enough to get me into trouble when the water gets rough. It will pull a 1715 but does get a little warmer, so I prop down to be safe and finish the race. But on the last heat of our race, I decided to see if the rewind was actually any benefit I was out of the running cause of a mistake or three anyway. So I put an ABC 1814-17-45 on it, HO LEE SHIP that turned it into a rocket! I don't know how hot it might have gotten cause I only made it 4 1/2 laps before I subbed it by being to aggressive, but man it was fun. I was all over the leader (Doug Smock) and he has recently motored up with a BIG TP replacing his old 1515 Neu.
So when John's post came up I figured this might be a good chance to get a spare. John's is an 82mm long version, vs my 74mm, but the extra length wont hurt anything in my boat, And the KVs are the same so if I did swap motors, I wont have to change props if I don't want to.
John agreed to sell me the motor cheap enough, cause it's just a paper weight to him now, I hope he didn't pay to much for it when he bought it. I got it in last evening and tore right into it and found the short right away Where the leg wire bundles wrap over each other on the rear of the motor. There was a little bit of black residue and two or three blown wires. And on the PTO side there was also a tiny spot with just one or two wires blown into. But what happens, when this happens, is that when a wire does get hot enough to burn the insulation off, then it also usually burns the wires that are pressing tightly up against it. And if those wires are on another leg, POOF! Now when the ESC is sending a positive signal on that leg, it runs into the short and either gets in the leg that has the negative side on it, or get into the OFF leg which is supposed to be sending back EMF the the ESC to tell it where the rotor is positioned. So either way the poor ESC can't figure out what to do, so you get the shuttering/ single phasing.
I'll post a few pictures as I go to try and show what's going on.
.... it's windings could easily be compressed.
Nortavlag Bulc 
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