how many agree that stator failure is caused by vibration ?

[admin]

ok, I could see that, there is a lot of room under the flywheel.
that gives me an idea,  what if you were to run an extra maybe half a quart of oil
in your engine. not enough to create problems but enough to
bring more oil up to the bottom of the stator...

there has to be a reason why some people haven't needed to replace a stator
and others need a new one every 2 years or so.


I like the scoop idea...

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.

[Rikugun]

In August, I met up with a forum member who was interested in a Bultaco I had. We got to talking about Visions (of course  :D)  It came out during that discussion he runs his 1/2 qt. over filled. He has been doing this for some time with no ill effects. Since then I've been doing the same.

I can't say if it helps with stator temps or not but I feel better knowing there is too much oil rather than not enough in the engine. Especially with the rash of rod bearing failures I've noticed of late.

[Rikugun]

It might be worth at least trying the heat sinks first, it's not like they cost a lot.

You may increase it's effectiveness with a dab of heat conductive goop like this (similar to the paste applied to the back of GM HEI modules):
http://www.ebay.com/itm/Thermal-Grease-Paste-Compound-Silicone-fr-CPU-Heat-Sink-/390166457118?hash=item5ad7bbab1e

[admin]

well see, now that is an interesting idea.
the book says 3.6 us capacity I'd say bumping to 4 qts would be a worth trying
and see what the long range effect is on the stator.
one downside I see is having more blowback oil in the air cleaner.

anything else ?

In August, I met up with a forum member who was interested in a Bultaco I had. We got to talking about Visions (of course  :D)  It came out during that discussion he runs his 1/2 qt. over filled. He has been doing this for some time with no ill effects. Since then I've been doing the same.

I can't say if it helps with stator temps or not but I feel better knowing there is too much oil rather than not enough in the engine. Especially with the rash of rod bearing failures I've noticed of late.

[Rick G]

!0 years ago , while in OR. i modified a clutch cover , so that it had a port to fit  a thermocouple from an electric thermometer. I wanted to check engine oil temp. Maybe I should have put it on the stator case. I'd like to do it on the VX , but I have no spares for it.


Ron , if you add more oil , perhaps using a catch bottle would be better than the stock setup, into the air box.

[QBS]

Isn't V oil capacity supposed to be 2.9 qts?

[rm97]

Engine oil capacity:
-Periodic oil change, 2.4L (2.1 Imp qt, 2.5 US qt)
-With oil filter replacement, 2.7L ( 2.4 IMP qt, 2.9 US qt)
-Total amount (right after a rebuild), 3.4L ( 3 Imp qt, 3.6 US qt)

On the topic of cooling the stator... I have made some significant changes to the design of the dune buggy I'm powering with a Vision engine, and I now have lots of room for cooling fins. I could even run an external alternator as suggested, but I just bought a new stator, and I would have to deal with making an adapter to run a pulley off of the crank.

[Walt_M.]

No, vibration does not cause stator failure in Visions. Heat does. The original Vision stator was built with epoxy that could not withstand the heat generated in the Vision. Yamaha later came up with a replacement stator with epoxy that could withstand higher temperatures. They were expensive and most people did not buy them. Do not under any circumstances buy a used Vision stator as it is probably a low temp model and well on its way to failure.
MOSFET, metal oxide switch field effect transistor. If the MOSFET does what its name says it does which is interrupt the stator current output instead of shunt it to ground, the stator may run cooler due to lower current in the windings. I may try one if(when?) my original '83 stator fails but I do have a higher temp OEM Yamaha stator as a replacement so I am not sure.

[YellowJacket!]

well see, now that is an interesting idea.
the book says 3.6 us capacity I'd say bumping to 4 qts would be a worth trying
and see what the long range effect is on the stator.
one downside I see is having more blowback oil in the air cleaner.

anything else ?

In August, I met up with a forum member who was interested in a Bultaco I had. We got to talking about Visions (of course  :D)  It came out during that discussion he runs his 1/2 qt. over filled. He has been doing this for some time with no ill effects. Since then I've been doing the same.

I can't say if it helps with stator temps or not but I feel better knowing there is too much oil rather than not enough in the engine. Especially with the rash of rod bearing failures I've noticed of late.

Hmmm...  I've always filled mine with 3 quarts at each change.

David

[Walt_M.]

Mine is full at just under 3 qts. and my stator is original.

[fret not]

Between Walt and David it is beginning to sound like less oil in the crank case is better for the stator.  This is a puzzlement. ???

[admin]

well actually no, not that surprising because I wouldn't expect anyone intentionally
overfilling their bike and so we don't have any accurate data yet.
we do agree on heat being the problem but its not that obvious.
the heat is generated electrically, compounded by engine heat to reach the melting point.
I asked the question that hasn't been answered directly yet.
how long in a 300 degree oven can you bake a stator before it fails.
if the coatings are good quality with a high enough temp rating,all things being equal,
I'd say the answer is forever.
if it is marginal along with resistance from a lousy battery or a failing plug connector
the answer is not very long at all.

one thing to think about is that the ignition pickups sit right next to the stator and are
exposed to the same environment, we aren't having many of those fail.

what would be nice if we had a way to determine if the regulator was malfunctioning
enough to overheat the stator...

Walt are you also running a stock regulator ?

[Rikugun]

Between Walt and David it is beginning to sound like less oil in the crank case is better for the stator.

Two data points does not make a thorough study make.  ;D By that criteria the gentleman I referenced and myself both running 1/2 qt. heavy proves it works! I think the whole point of this discussion is a few have had long lived stators but no clear pattern has been established to show what the right ingredients are for success. And just to be clear I'm not recommending anyone overfill their crankcase although I will say a little too much is always better than not quite enough!  ;)  :P

Ron your comment of cause and effect as it relates to R/R is important. I've been struck by accounts of members installing stators (often used) every several thousand miles but sticking with the same regulator. Another fun game is one component goes bad and is replaced only to have the other fail some time later. Unbeknownst to you it's lifespan has been gutted as a result of the added stress placed upon it by the failing of the first component. You play this game for a few seasons alternating between replacing one then the other....  you get the idea.  :'( I don't pretend to be trained in electronics but have always felt that one bad component can effect the other parts of the system.  I'm sure the up front $ factor of replacing 2 expensive components is an issue but I'm at the point now that replacing one without the other can cost more in the long run.

Along the same lines is the question of battery condition. Some hang on to a failing battery by charging while not in use and relying on a higher than normal charge rate while riding. To me this puts undue stress on the charging components. Now here is where a "heated" debate on heat ensues....shunting vs not, high draw halogen bulbs helping or not, heat generated and how much when charging or not , blah, blah, blah. etc. etc. Bake a pie eat a pie.  I say if the battery won't hold a charge, replace it.  :laugh:

Walt's R/R may be stock with a PC fan? Others with a factory R/R sans fan still have good success while others not so much. Same with factory stators - a few have great success while most don't. When it comes to charging system woes there are so many variables at play, a definitive answer may never had. It's still good to have the discussion and interesting theories are suggested.

[admin]

heh,  exactly.

I do want to throw a couple more items into the mix.
for guys that have had long lived stators.

1. how long is the average trip you take on the bike?

2. do you typically park it on the side or center stand?




and just for the fun of it, lets make our own damn stators,
here is a stator winding machine for sale, anyone interested ?

http://www.alibaba.com/product-gs/510097629/2012hot_sale_motor_Stator_winding_machine.html


:D ;D :o ;D :D

[fret not]

HAH!!!  And it's in China yet.  Something tells me that could be an expensive proposition.  Did you notice method of payment listed money gram, etc?  No mention of bank wire transfer or other safer methods.

[Rick G]

Some people have wound stators by hand (on this forum about 8 or 10 years ago , with good results. Ihahve the wire and  the information some where. Its not all that hard . Some counted the number of turns of wire removed  and some measured the length of removed wire.  Lots of pics are needed while removing the old wire to get the pattern right. As i said , I have the docs on it if anyone wants to try.

[supervision]

  If I was going to wind my own stator, I would try to come up with a special low performance wind.  We don't need as high of out-put as these make now.   One time, Dwight, out-put tested mike bike, he showed me,  it was putting out  20 amps, at 4000 rpm.  I am pretty sure around half that would be enough.

[Extent]

how long in a 300 degree oven can you bake a stator before it fails.

If only the vision internals could be subjected to a steady state 300*.  In the real world it undergoes frequent heat cycling, which itself can be very damaging.  And if you're assuming 300* surface temperature from your readings that doesn't speak to the internal coil temperature of a fully loaded stator.

[supervision]

  I'd bet that  finning the whole case, would make a big difference.  Just think how important the finns on the r/r are. 

[George R. Young]

The three I had fail seemed to be heat related, once they get to crisp, the crummy varnish insulation on the windings break down and the wire shorts to ground.

If I was going to wind one, I would use wire with some high-temperature insulation, e.g. teflon, ceramic.
http://www.phoenixwireinc.com/ptfe-wire.html
http://www.ceramawire.com/applications.shtml
The teflon is rated at 260 deg C and the ceramic at 1100 deg C. Either should be good enough.

If you're going to all the trouble of winding the thing, it doesn't make sense to reuse the same varnish insulation technology that has failed repeatedly in this environment.

The question I always ask myself is, having knowledge of the stator heat failure problem, why didn't Yamaha do this?