how many agree that stator failure is caused by vibration ?

[admin]

yes it's a dead horse, lets keep on beating the crap out of it  ;-)

here's an idea...

http://www.vulcanforums.com/forums/showthread.php?t=24679

this person states the reason for stator failures is vibration, not load, not heat, perhaps
this is the real reason after all.   the vision vibrates, live with it...
comments ?




if that be true,  how many think moving the regulator to a different spot has or will increase stator life ?

[Lucky]

I think it's heat mostly. Most of the dead stators I've pulled we're crispy at the top. I think they see less cooling oil there. I installed an oil cooler 8 years ago & the the Yamaha replacement stator is still going strong (knock wood)

I think moving the R/R TO COOLER AIR ALSO HELPED AS DID A SEMI SYNTHetic oil and eliminating the R/R connectors.  (oops. Sorry)

Tourer generally runs just past center on the temp gauge & the fan only ever comes on after the bike is off on a hot day. I made sure to flush the cooling system and burp it well. I also tend to set my carbs slightly rich. That might contribute to it running cooler. It recently got an Agm battery and I'm hoping to put a MOSFET R/R in someday...


Sent from my iPhone using Tapatalk

[Rick G]

Well, the Vision has a counter balance shaft and is very smooth and nearly vibration free. My VX  has either a staggered crank pin or nothing at all. It generates quite a bit of vibration above 7000 rpm and at 8500 red line is actually a bit uncomfortable. Both use the G7 stator.
My VX had a factory stator which failed after 21 years of use, It had 3 coils which were brown , none were cindered. I installed a used  stator from a  750 Virago. The RR is stock, but is moved to a location in front of the left rear shock , for better access and air flow . ( stock location is down by the swing arm in front of the rear tyre.)
The VX forum reports a very occasional failure , Not a chronic problem .

I installed a KZ900 RR, on the Vision, in 2003, It has a larger heat sink  and is supposed to be better quality.  I moved it  out in the air stream , on the left foot peg /muffler mount. Both RR are hard wired in, as are the stators.

As I said many years ago on this forum , the Vision 's oil runs fairly hot. The  oil is not present in much of a quantity to carry heat away from the stator ( the VX has much more oil in the stator case) I believe that the heat build up in the case results in premature stator failure. The oil needs to be cooler that the stator to carry the heat away. Either there is not enough  oil to do this OR the oil is too hot and is actually adding heat to the stator. The G7 stator used in the Vision , is used in lots of other bike's, 4's, twins and singles. Most have a low incidence of failure.
I don't believe vibration has anything to do with it.

[fret not]

I think Rick is correct that vibration is not the cause.  It COULD be if the stator windings were loose and flopping around but that is not the case.  Most failed stators are quite dark in color, crispy and blistered even.  I think heat is the usual cause for failure, though there can be other reasons. 

Here is a good application of the much heralded MOSFET RR unit.  Since the MOSFET units run cooler than the original RR units that shows me they are dissipating less heat, which leads me to believe they cause less stress on the stator.  All the components in the charging system form a "chain", and by strengthening the weakest link the whole becomes stronger.  That's my conjecture and I'm sticking to it.

[rm97]

This may seem like a somewhat radical idea, but what about having a machine shop drill a small hole diagonally through the flywheel, and into the center of the crank. This way the stator would be continuously sprayed with oil, all the way around the innermost side of the stator. Would that cause any problems to the rest of the oil system?

As already mentioned, the stators are usually burnt out at the top where little oil reaches it, causing me to believe that the main problem is that oil is not reaching the stator. Adding a mosfet r/r help keep the stator itself running cooler, and adding an oil cooler helps cool what ever oil reaches, but if the top half of the stator is receiving little oil it is still likely to burn out. If a lot of people think this is worth trying I might give it a shot, especially if I'm already having my crank ground down.

[admin]

not radical at all, in fact a version has been done on the Venture.
a couple of the guys here have tried it but I don't recall if they ever posted a long term result.
personally I think it's inconclusive and I wouldn't want to risk modifying the oiling system
on the vision only to have a crank failure...


I agree that vibration isn't the real culprit, of course it is heat.
the difference is that we have some great minds around here and some excellent ideas
I really just wanted to stir up some further discussion on the topic



Rick, I understand what you are saying but is the suzuki stator completely immersed in oil ?
if the oil level was that high in the crankcase wouldn't that be a big power loss for that engine ?
does suzuki spray the stator in that motor ?

RM, Id tend to doubt that the oil is necessarily any hotter in a vision than any other bike, especially an air cooled one.
cooling oil that never reaches the stator would also seem a time waster.  perhaps there is a way to funnel returning oil down over the stator on its way back to the crankcase...     thoughts ?


-Ron

[YellowJacket!]

So, I am probably going to wake up some nasty, hungry gremlins by saying this.....  It'd be interesting to compare a Vision that has not burnt a stator to one that has burnt several.  So, given that YJ is still on the original stator, anyone close to TN that burns a lot of stators is welcome to have a seat on YJ and see if there is a difference between the two in vibration.
IMHO, YJ does not vibrate a lot so its a viable theory.

David

[Ken Williams]

Any way to get the stator to run cooler should improve stator life.  An oil cooler should reduce crankcase and stator temperature, even if not much oil actually gets to the stator.  The type of regulator in use could have an effect also.  Most regulators are of the shunt type.  Unneeded phase current is shorted to ground.  With a series regulator unneeded phase current is switched off.  The lower average current flowing in a series regulated stator should lead to lower stator temperature.  The Compufire 55402 appears to be a good Vision series regulator candidate.  Assuming the MOSFET regulator discussed previously is of shunt design it won't directly improve stator life.  However, it should be more reliable than a before MOSFET design. 

[rm97]

perhaps there is a way to funnel returning oil down over the stator on its way back to the crankcase...     thoughts ?

If you wanted to try this I think your best bet would be to catch oil coming down through the rear cylinder cam chain chamber. The biggest problem would be making something that can catch most of the oil, and still allow clearance for the cam chain. Once you did that you would have to get the oil,between the flywheel and the stator cover which are very close together, and then around to the inside of the flywheel. The other option would be to try and take oil from the starter clutch bearing, which currently splashes oil back to the sump. If you could get this to work it might be a very good option, but I think getting it to work would be complicated.

I still think that adding a small hole as I mentioned would be a better/simpler option. Would it really be that much of an extra load on the system? The particular oil gallery it would be taking oil from is currently only supporting the starter clutch bearing, and is fed by the left side main bearing (which also feeds the front cylinder head through a small oil jet). Right now the starter clutch runs on a bushing with grooves in it, these grooves hold oil and allow oil an easy path back to the sump. Maybe using a bushing without grooves here could make up for a pressure loss caused by adding the extra hole in the flywheel?

[Rikugun]

I think it's good to beat a dead horse  ;D There are always new members with fresh perspectives to add their 2 cents.

darkvision added heat sinks to the alternator cover and seemed to get measurable temp differences with them. Here's a pic in this thread:
http://ridersofvision.net/rovforum/index.php?topic=13269.msg120545#msg120545

He first mentioned it way back in '08 http://ridersofvision.net/rovforum/index.php?topic=9564.0and quite a lengthy discussion ensued that ran the gamut of theories. Page 2 has a pic from George Young showing where he drilled his flywheel bolt to spray oil on the stator. A subsequent stator failure had him comment the results were inconclusive.  Page 3 has a reply from motoracer with oil temps he measured that suggest an oil cooler is superfluous.

Lots of interesting reading on the subject.

[rm97]

Did George do any other modifications besides drilling a hole in the end of the bolt. If not I do not think his modification would have had any chance oil getting extra oil to the top half of the stator. When the engine is assembled that bolt is enclosed in a little circular area, making it impossible for the oil spray to hit the stator directly. That said I didn't see anything about indications of low oil pressure, so that could provide me with some reassurance to try my idea.

I really like the heat sinks! Something like that could work very well for me, although I'm not sure I would have the room/airflow for it to work well. I wonder if I could pipe coolant that had gone through the engine already around the stator cover... I just checked and I think the coolant would be too hot for it to really cool the stator cover.

[admin]

ok, lets look at it from another perspective, you take your stator
and you stick it in a 300 degree oven.
how long before the insulation breaks down and shorts to ground ?

a week ?
a month ?
a year ?

what if the insulation is rated for 500 degrees ? 
where does that leave us with the heat idea, heat from
outside of the stator or heat from inside the stator.

do we know what the insulation temp rating is ?

do any of the manufacturers mention this ?  I haven't seen it

so is the insulation on a stator made by Honda a better grade than Yamaha ?
Didn't honda have more regulator failures but fewer stator failures ?

we have a lot of data available to us, being able to quantify it is another story.

[cvincer]

Here we are ............... stick on heat sinks from  Jaycar, part No  HH8580

[George R. Young]

Did George do any other modifications besides drilling a hole in the end of the bolt. If not I do not think his modification would have had any chance oil getting extra oil to the top half of the stator. When the engine is assembled that bolt is enclosed in a little circular area, making it impossible for the oil spray to hit the stator directly. That said I didn't see anything about indications of low oil pressure, so that could provide me with some reassurance to try my idea. . . .

Had the bolt drilled for oil flow but no other modifications to cool the stator. This was BTW the modification Yamaha prescribed for the Venture so it must have some merit.

http://web.ncf.ca/ag136/bolt.jpg

Don't really know if this helped because I sold the Vision.

[Rick G]

Ron , the  amount of oil in the stator case in the VX is higher than the  Vision , IE, the drains are farther up in the centre case , I assume that this causes more oil to be thrown up upon the stator by the rotor, but not so much that there are excessive  pumping loses.

A wild idea that I came up with , was to add a hose from a scoop , running to the oil filler , then add a fitting to the top of the stator case and run a hose to the air cleaned or a catch bottle, This would ventilate the crank case and circulate cooler air around the stator . This may cause  too much oil migration out of the crank case , or there might be other problems, BUT it would cool the stator.

[rm97]

Do you guys think that the vision's water pump could handle adding an extra (small) coolant line running from the pump, through a small water jacket around the stator cover, and back to the radiator? Does that sound like a somewhat sane idea, or would I be robbing too much coolant flow from the cylinders? This would be more complicated, but not as risky as the oil sprayer idea. Please keep the ideas coming, I really like conversations like this!

Ron, I would think that the fact that the heat cycles from high to low has something to do with the failure. I purchased a rebuilt stator, so I could possibly get specs on the wire used on it. Someone could try running the bike with the stator (or flywheel magnet) installed, and without it installed, this would then tell you if the heat is generated by the stator.

[Rikugun]

If you suspect heat is the issue, taking an active assault with liquid cooling jackets may be beneficial but it seems needlessly complicated. You might get more bang for the buck going after the heat sink idea. Just my 2 cents. Since you asked  :)

[rm97]

If I was keeping the engine on the motorcycle I would love to have the simplicity of the heat sink, but I'm not sure they will get enough air flow with my setup. That said, considering that these are all external mods, they could be changed around pretty easily. It might be worth at least trying the heat sinks first, it's not like they cost a lot.

[supervision]

  I in my opinion,  another alternator, outside the case, driven by  toothed belt would make a big improvement, over the ell-cheep-o style of magnet we have. They did a nice job with the engine design, butt handed us a turd for a charging system.

[supervision]

  On ebay 91-03 zx7 is the style that could easily be adapted