Generator woes

[SoloFrenos]

Hi everyone, I went out for a ride today and after about 10 miles my bike died, and when i kicked it over you could tell it was not sparking, so took a plug out and sure enough no spark. After being recovered home I took off the flywheel to discover this!! Has anyone else had this happened to their generator or am i just unlucky!!

Time for a beer! Tony

[Pat]

No but it looks like it's happened to that one before, think that's been "re-wrapped " by West Country windings. When you get it re-wound, use someone who doesn't burn the old stuff off.

[EVguru]

I don't think that's a Morini stator. I have one like it and it's supposed to be something ex-Ducati.

[norbert]

This is the "bodyless" alternator, the last evolucion of Ducatti Elettronica para Morini. It´s the best you can get, about 200W!

You fixed the cable with that little metal plate that normaly goes with one of the three screws (the left one) that fix the alternator? With that plate you avoid the cable to have contact to the flywheel.

norbert

[SoloFrenos]

Well as far as i know its a standard morini one of an early excalibur (ie on with the starter under the right hand cover) engine but i suppose a previous owner could have swapped them or something?

The issue though was not that the flywheel cut through the cables (metal tab present and correct), the problem is the three 'rivets' holding the windings to the backplate have sheered off and the windings stuck to the magnets and thus spun round ripping the wires out!

It was recently re-wound by west country windings, but judging by the state of the green insulation that was there before i send it to them,I'm not sure how they would have burnt the old stuff off without burning that away. But i guess if they had burnt off the old windings that could have weakened the rivets, maybe??

Its ironic that i had it re-wound as i decided to replace the existing Kirby/boyer igniton with an original type system, the Kirby one had been on for over 10 years with no problems - oh just to clarify that statement, I'm not implying that the new ignition system had anything to do with the failure, just ironic that I replaced it with something better only to suffer my first recovery in over 10 years )

[norbert]

That´s bad luck, I´m sorry for that.

The alternator is the one who goes with early Excalibur, that´s correct. It has to be used with the "bridge"-regulator with a B+ port (28A, when I remeber it well)

norbert

[Ralph]

Looks to me like the stator as been touching the flywheel, it
gets hotter expands till it ether snaps the rivets and twists or
grinds the engine to a stop, maybe the rivets came loose and
allowed it to touch, was the flywheel tight, does it run true,
could there be play in the mains? could the regulator have
gone and allowed it to get hot enough for it to touch the flywheel?
seen it a few times but not
on a Morini.

[Pat]

I've had rewound one's on several bikes, no morini tho, and if the insulation is burnt off its usually leads to later issues, yours has almost certainly been burnt off and hand rewound if done by West Country, . The Green powder coat is usually re-applied post burning off. Get it re-wound at rexs rewinds, they use a non aggressive process to remove everything and the rewind will be done by machine. 01580 880768 is the number.

[SoloFrenos]

the plot thickens, I spoke to West Country Winding who said that they do not burn of the old windings on Morini alternators, they are disassembled by hand. So that can be discounted as a possible cause. On inspecting the flywheel there is only a mark about 1/3rd round where something has rub against it most likely from when the final rivet gave way, which i would think means that they where not rubbing against each other for any period of time, ruling out heat/expansion/rubbing. It is looking more and more like a simple case of the rivets giving up through old age. But West Country are going to look at it to see if if salvageable without a complete re-wind, so all is not lost. Interestingly on the 'special'one they made for me for the boyer ignition the rivets were replaced by bolts.

I also realised that with more irony, had i still have had the boyer ignition on, i would have been able to ride home rather than having to wait 4 1/2 hours for a recovery. Ho hum, sometimes things are just best left alone!