How long does the stock r/r typically last ?

[posplayr]

Nippon denso sold Suzuki junk for years and gave the GS a bad reputation.

I agree with this EXCEPT I'd have to rephrase "The stator runs in hot oil". It doesn't. It is just oil dripping off the shaft for lubrication I think. It is returned at the bottom of the casing.

Pehaps this oil stains the windings but varnish can be quite dark and work fine, oil or not.
I've several old electric shop motors around from the 50's-one is from the '30s- they have very "dark" varnish but they work fine.
Mind you, if I unwound these, it's plainly brittle!

It's a wonder to me nobody has glued a heatsink oto the casing..correction: no one except me? I glued one on the 400E for a lark....as to if it does any good? can't say. [ATTACH=CONFIG]53825[/ATTACH]

I have read here that the Hayabusa has a drilled out crankshaft to spray the stators. My own sprayer was very effective. People do not realize that the positive feedback mechanism that can lead to stator overheating. Even for a constant current, a higher temp creates a higher resistance which creates more power loss in the stator heating it more, which increases the temperature and continuing the cycle. 280 degF oil is actually cooling oil and seems to reduce the operating temperature by a noticeable amount.

[Gorminrider]

Here's an ugly that was in my 400T when bought...WHAT was going on? but it still worked fine. IT had had a new regulator. Note the oil so familiar..original stator 400Tcloseup-see string-june28-2014.jpg

[posplayr]

Here's an ugly that was in my 400T when bought...WHAT was going on? but it still worked fine. IT had had a new regulator. Note the oil so familiar..[ATTACH=CONFIG]53826[/ATTACH]

It clearly has two burned poles/windings at 9 o'clock. That is not oil damage. Just because it seems to work doesn't mean that it has not been compromised. You don't have a baseline measurement to compare it to from when it was new. This is clearly not oil damage/ aging.

[GSXR7ED]

Good info on here as always for electrics.


Ed

[Gorminrider]

and here's a nicer one from a parted 650G (50000km) Is it oem? Don't' know if it's a replacement... oh well still works but I keep it as a spare. I sort of wonder if those globs of varnish won't crack if it's so hot in there?

[Gorminrider]

It clearly has two burned poles/windings at 9 o'clock. That is not oil damage. Just because it seems to work doesn't mean that it has not been compromised. You don't have a baseline measurement to compare it to from when it was new. This is clearly not oil damage/ aging.

No it surely isn't!! What's amazing is someone was apparently able to fix it. as to what "they" did or why. The unwinding of it wrecked any practical investigation.

But I do know it "worked" as in charged battery at something over 14vdc without mishap for 10000km until I replaced it -really, merely so I didn't have to see it again..It seemed to test ok .

[posplayr]

No it surely isn't!! What's amazing is someone was apparently able to fix it. as to what "they" did or why. The unwinding of it wrecked any practical investigation.

But I do know it "worked" as in charged battery at something over 14vdc without mishap for 10000km until I replaced it -really, merely so I didn't have to see it again..It seemed to test ok .

It may not be obvious to you, but it is quite clear to me and not worth any further discussion. Those are burned windings; period!

[Brendan W]

Shunt makes little sense to me. Basically you are using fuel to heat the oil and giving all sorts of connectors and insulation a work out at the same time.

Are they just cheaper to make ?

[posplayr]

Shunt makes little sense to me. Basically you are using fuel to heat the oil and giving all sorts of connectors and insulation a work out at the same time.

Are they just cheaper to make ?

Before micro-controllers got so cheap ($0.10), it would have been much harder to implement a Series R/R. The classic Shunt R/R is made with SCR's which provide most of the control function requiring only a zener controlled feedback for SCR turn on.

Series R/R needs to do what is called synchronous control which means it has to estimate zero crossings for on-off control of the MOSFETs. This requires a small controller for timing. Today that cost is inconsequential. Ironically the MOSFET shunt R/ R also has to do a synchronous operation to implement rectification. By what would amount to a small firmware change in the controller algorithm most MOSFET R/R could have implemented Series control without much alternate consideration.

The only reason to still install a Shunt R/R is market inertia. There have been some Series R/R that are not capable of keeping up with high speed motors at 16K RPM. This is a design limitation of a specific implementation and can be easily corrected with a faster controller. Does, not effect any GS that I know of.

[metalfab]

Someone needs to make a Polyimide insulated stator. They use a magnet wire with 4 layers of Polyimide it can withstand 464F, in a lot of aircraft applications. The SH775 is a great move.

[posplayr]

Someone needs to make a Polyimide insulated stator. They use a magnet wire with 4 layers of Polyimide it can withstand 464F, in a lot of aircraft applications. The SH775 is a great move.

An oil sprayer is as effective if not more than the series r/r in improving stator longevity. That is because it reduces the power in The stator . Lower temp is lower resistance and lower power.

[Nessism]

Kawasaki KZ bikes don't often burn out stators and/or R/R's despite using the same permanent magnet generator and shunting R/R technology. Many of these bikes, such as the popular 650/750 models, don't oil cool their stators either. The stock R/R's are typically Shindengen SH230's or similar, the same basic style duaneage sold by the hundreds here, which are very robust. I'm not positive why the charging system is so much more robust than the GS's but I think it's at least related to the lower power output of the generator; less power means less shunted (excess) power that flows back to the stator. KZ bikes don't have that stupid stator loop that sends power into the hand control either.

[posplayr]

Ed , there should be no big mystery. As I have described the operating temperature of the stator is very dependent on the amount of cooling available. A small increase in power or loss in cooling (e.g. Low oil level) results in a much higher operating temperature at the stator. That increase temperature increcreases resistance further increasing power.

the limiting factor in output power is the current rating of the magnetic rotors. Given all the same components and even similar loads , a 10% higher current rating on the stator could result in much higher incidence of burned out stator. This is in the case of shunt r/r because the 10% excess current is squared in power and largely is disapated in the stator.

bottom line , and history has shown that, there can be widely varying results depending upon bike, rider and other factors. This explains why almost anything you can do to improve stator cooling helps so much.

[Nessism]

Jim, like I said, the KZ550/650/750 do not cool their stator with oil. The stator is located on the end of the crank sealed inside a small cavity with zero airflow yet these bikes rarely burn out stators. On GS bikes the only oil that hits the stator is a very small about of splash intended to lubricate the starter clutch. There is no active cooling for the stator on any of these bikes.

[posplayr]

Jim, like I said, the KZ550/650/750 do not cool their stator with oil. The stator is located on the end of the crank sealed inside a small cavity with zero airflow yet these bikes rarely burn out stators. On GS bikes the only oil that hits the stator is a very small about of splash intended to lubricate the starter clutch. There is no active cooling for the stator on any of these bikes.

I got all that. My point is quite simply that subtle factors can have dramatic effects on stator temperature. The same reason why you 1000 did not see a temperature drop when several people have reported drops in 1100's from using a series R/R.

All you have to do is calculate the power dissipated in a stator due to a 10% current increase and a 100 degF temperature rise.