Yet more charging problems

widget
Posts: 164
Joined: Wed Apr 14, 2010 10:28 pm

Yet more charging problems

Post by widget »

Have a kettle that has an ongoing problem. It seems to 'blow' the rotor. Had several on the bike now, including newly rewound ones.

I have a combined rec/reg (tried more than one) brand new motobatt, been through the harness from headlight to tail light, cant find any duff connections. Brushes are good, put new electronic ignition on, to see if that made any difference..

Puts out about 14.5(bit less with lights on) when new rotor is fitted.

Second ride out this year, which was only about 10 miles, and problem returned, Missus is fairly peed off with the bike now, so need to fix it...

Have looked up charging problems on here and seem to have tried the fixes.

What could make the rotor go open circuit?....

Any suggestions gratefully received...
widget
Posts: 164
Joined: Wed Apr 14, 2010 10:28 pm

Re: Yet more charging problems

Post by widget »

hmmm....just had the rotor off and both wires are broken off the coil..not off the slip rings, but inside the shark teeth bit.....now..this is not the first time this has happened.. can something make the rotor coil get hot so the joints melt... or vibration off the crank?......
User avatar
Waterbuffalo
Posts: 1090
Joined: Sat Nov 12, 2011 1:01 am
Location: Mostly Barbados, often Florida and ocassionally western Canada; trust me,I get around.
Contact:

Re: Yet more charging problems

Post by Waterbuffalo »

A suggestion is to check the engine earth strap first. Also check the earth on the harness under the tank, as well as the short earth link from the frame to the electrical panel as thats very important. If you look at the schematic, the slip ring brushes connected to the rotor are linked via an earth (engine through earth strap) at one side and the green wire to the regulator on the other.
Wiring_GT750B.jpeg
Two strokes, its just that simple.
User avatar
Alan H
Posts: 12104
Joined: Fri Aug 05, 2011 6:38 am
Location: Wombwell, Republic of South Yorkshire

Re: Yet more charging problems

Post by Alan H »

If the reg is supplying too much power to the rotor, it will overheat. You might need a wire 'direct' from the battery to the reg, via a relay - so the power is switched when the ignition is on. This should put true battery voltage to the reg, not battery voltage less all the resistance from the battery through the fuse, connections, ignition switch, kill switch and back down the orange to the reg. Or just fit a proper regulator. They work fine.
Did the wires on the rotor break or did the solder melt? Wires shouldn't break for no reason.
Proof that four strokes are over complicated
widget
Posts: 164
Joined: Wed Apr 14, 2010 10:28 pm

Re: Yet more charging problems

Post by widget »

Thanks for the replies....

Update today.. Put a newly rewound rotor on and all as charging as should be...However, have done that several times before and doesn't last..so need to sort this problem out once and for all, as the wife is getting pretty disheartened that her bike won't run properly...

Two rotors have had broken/ un soldered wires, though on one rotor, the coil was moving inside the metal part, so i assumed the movement had broken the wire.. The latest one, the ends wires that go from the rings into the body of the rotor were flung out to the diameter of the teeth part, cant see that both had broken at the same times, so chances are they must have got pretty hot to melt the solder!!!... Not sure if the first ones coil had got hot and lost its glue or just unlucky the coil moved..

I never checked any of the other rotors for broken / un soldered wires as nothing was obvious.

I put a clock on the taper to see if there was any run out...runs less than a thou....The slip rings runout about 2 and a bit thou... did that just to check if there was vibration causing probs...

Have been through all earths as I know duff ones can cause issues..Though didn't know there was one from the panel to the frame...will look at that in the morning..

I am the first to admit that lectrikery is a dark art to me, so wiring diagrams just like like a snakes wedding!!...

I have tried 3 rec regs on this bike, including one off of mine, so not sure if they could all cause the same problem, but will go 'standard' to try anything...both bikes came without half the electrical bits so just put a combined one on from the off..

Is there a pic of the standard setup any where?...

Is there a pic of the extra wire/relay anywhere?

Thanks
Last edited by widget on Sat Apr 29, 2017 9:21 pm, edited 2 times in total.
User avatar
Waterbuffalo
Posts: 1090
Joined: Sat Nov 12, 2011 1:01 am
Location: Mostly Barbados, often Florida and ocassionally western Canada; trust me,I get around.
Contact:

Re: Yet more charging problems

Post by Waterbuffalo »

So you confirmed the grounds are good, so now I'm curious as to what voltage you are seeing on the orange wire at the regulator connector. With the ignition on engine off, with the engine running lights off, and then with the engine running and lights on.
The coil needs to be fixed firmly on the rotor, any movement will cause a rupture to a wire due to vibration. Suzuki had some issues years ago with faulty coils fitted loosely in the rotors, there was a service bulletin about it.
Two strokes, its just that simple.
widget
Posts: 164
Joined: Wed Apr 14, 2010 10:28 pm

Re: Yet more charging problems

Post by widget »

will go and have a play and see what i get....

I am assuming it is the wire in the same block as the 3 yellows...

12.2 engine off/12.4 running lights off /12.1 running lights on
User avatar
Waterbuffalo
Posts: 1090
Joined: Sat Nov 12, 2011 1:01 am
Location: Mostly Barbados, often Florida and ocassionally western Canada; trust me,I get around.
Contact:

Re: Yet more charging problems

Post by Waterbuffalo »

There does not seem to be much voltage difference between the battery and there at the orange wire to the regulator from your readings. A lower voltage (10 to 11 volts from high resistance situations in the harness causes the charging system/regulator to work overtime and boil the battery. That sort of situation which was a common problem would still not cause the rotor to burn out. I can only suspect you had a rewind job on that failed rotor where the wires were not wrapped tightly enough and then sealed in with resin correctly.
It will be intersting to see what this replacement rotor does, as from what you are saying, everything else seems to check out to spec.
Two strokes, its just that simple.
widget
Posts: 164
Joined: Wed Apr 14, 2010 10:28 pm

Re: Yet more charging problems

Post by widget »

That's the frustrating bit :oops: .....it all seems to check out ok, but eats rotors.....probably put 6 or so different ones on it...old ones, new ones, still end up swapping batteries to get her home..I can't imagine that I am unlucky enough to have put on 6 or so dodgy rotors that just happen to let go......There has to be a fault somewhere.

The rotor that has just failed was not a rewound one, but it had been on my bike for several years without problem...put it on her bike and it failed in 30 miles!!..can't be that unlucky surely...

Going to change the generator, just to try something...is something on that going wrong when it gets hot and frying the rotor?.....don't know...could it?...

..Will see if i can get original rec regs for it...again, just to try something.

...got a new rear harness coming...just to try something.

...It is getting to the point where she doesn't want to ride the bike and she loves her bike..so I have got to keep trying..


I would love to have a eureka moment where I find some hidden melted bit, but chances are that won't happen..
teazer
Posts: 1035
Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Yet more charging problems

Post by teazer »

Earlier posts suggested a wrongly rewound rotor, but for an older and fully functional rotor to fail suggests that may not be the only issue at play.

With the bike running, what is the voltage at the brushes? And what is the voltage at the lead going into the regulator from the coil/switch? The first is output from the regulator and the latter is the sensing voltage that triggers the regulator.
Post Reply