Yep..I know this has been done to death but the fixes as you suggested earlier don't seem consistent, with bikes fitted with stock items having a longevity that others don't enjoy with "improved" parts fitted.
Looking on various forums, the Aprilias also suffer with burnt stator or RR issues as do various Triumphs, Suzuki and Harleys...
Also I read, and it seems to make sense to me, that fitting led lights with their lower current needs also places extra workload on the RR so fitting heated grips, running lights etc helps reduce the "extra" power the RR has to dissipate.
The one piece of conclusive evidence I have seen is an 1125 owner took a thermal image of the ignition side of the engine in similar ambient conditions : one with the stock set up and one with a modified rotor and series RR and the temp difference was very noticeable....it was also mentioned that the coolant temp had reduced so I guess the effect of the stator acting as an oil heater in it's normal stock mode of operation is clearly seen. If the series RR open circuits the stator when not required it can't generate heat.

_________________
Caution: I run with scissors.

Can you buy lower rated MOSFET RRs than the one you have?

_________________
08 Specialized Langster

They seem to be rated for current.....30A or 50A being the most popular.....I doubt buying a lower rated one would be good for the RR unit.....plugging in a 30A unit into a generator capable of outputting 50A seems a way of frying it quickly!
Now I see why a cars alternator is a winner over a permanent magnet unit....... Varying the magnet strength to alter the output seems a clever idea....

_________________
Caution: I run with scissors.

Wouldn’t it just draw less current from the stator? Less current means lower temperature...

_________________
08 Specialized Langster

I can see what you're thinking here and I don't know the intricacies of the workings of the unit....the RR always seems to be spec'd to the max output of the generator.
Here's what I think I know : the generator output is always 100% (100% of its max output at a certain rpm, possibly 20A at 1500rpm and 30A at 4500rpm rising to 40A at 10k rpm for instance) and that 100% output (whatever ampage that might be), if it isn't required by the charging circuit or the bikes demands (lights, fans,ecu, injectors etc) is shorted to ground by a Shunt/mosfet RR allowing the stator to continue to generate amps/heat for no gain. If the RR isn't spec'd correctly then it will be short lived.

The 09 stator was wired for more output over the 08 stator and perhaps the reason some 09 bikes seem less prone to failure than others is due to variances in winding numbers, different riding styles, tolerances in RR components, connection resistances.......it may be a ragged edge system where just one small increase produces a cliff top moment ....The stator is at the high output side of "normal" and the RR gets hot, starts to fail, putting pressure on the stator, which gets hot and starts to fail..

Maybe someone with more electrical "noledge" can put it more eloquently & more accurately ?

_________________
Caution: I run with scissors.

Can a shunt regulator cause the stator to fail? just a thought but like you say the stator output is linked to engine revs and ALL of that output is either used or shunted straight to Earth at all times , if you lost continuity due to a failed RR then no current would be able to flow from the stator , if the RR failed to Earth wouldn't you still be the same as shunting the output to Earth like it does during normal running? I can understand the failed RR not charging the battery OR frying the battery but is it really possible for a failed one to do any more damage to the windings than normal running does anyway?

_________________
2001 X1 2009 1125CR 2006 Uly X3 2010 Uly a fully Maz'd S1 and a 1991 RS1200 Westwind.

I did a lot of work on this initialy when mine went, I use a compufire rec reg with cpu cooling fans fitted to the auxilary loom, in the normal position and my own oil spray system on the stator, rewind the stator in honda spec coating, have done a few of them about 8 all good mines hitting 48k now

_________________
A12 XBS, B 15 OUT !!

I've often wondered about this myself Kev, and would love to know the answer from someone cleverer than wot I am. If the windings went open circuit or the RR failed, would there still be an EMF to produce current?

_________________
If your dreams don't scare you, they are not big enough.

no.

_________________
Feros Ferio

nice....the compufire is a series RR I guess?.....and what's your own design oil spray system.....an external line connected to the cover ? (Apologies if you have shared this before)...

_________________
Caution: I run with scissors.

Received the 847 series RR from the US today after being stuck in customs for ten days.....grrr....fitted onto a heat sink mounted behind the number plate to ensure it remained cool and wired direct to the battery with an auto reset fused link on the power side.
Having charged the battery, I started the bike and the rewound stator shows a healthy 14.5v on the dash and after a cheeky test ride the RR stays cool to the touch rather than the previous toaster style reg under the seat.
Changed the oil and filter too and it may be the ambient temps have reduced from the 30C we had when I last rode, but the engine temps seem lower....probably all in the head....

lets see how long it lasts...

_________________
Caution: I run with scissors.

_________________
08 Specialized Langster

Here's hoping all is well


Churchill

Nice work. Good luck!

Position of the new RR

_________________
Caution: I run with scissors.