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Discussion Starter #1 (Edited)
I replaced my stator for the second time recently and while I had the engine open, I added an oil tube to douse the stator with engine oil. Hopefully, this will actively cool the stator and keep it from burning out. I live in Tucson and commute on the freeway and when the traffic backs up, the engine gets pretty damn hot.

I haven't actually driven the bike yet, but I warmed the engine up and removed the timing inspection cover and observed copious amounts of oil splashing about. In fact, the first time I started it with the cover off, I had to immediately shut it off and fabricate a splash screen to catch the oil being driven out from crankcase blow-by. There's a lot of churn going on around the flywheel, given that the timing chains are right behind it. I could see a solid stream of engine oil coming from the two oil tubes that I added, spraying the back of the stator. Oil also shoots past the stator and floods the cavity between the stator and flywheel.

Before I started the engine for the first time, I connected an oil pressure gauge. At idle the engine has 50 psi and at 4000 RPM it has about 70 psi of oil pressure, so there doesn't seem to be any pressure loss due to redirecting some for cooling the stator.


01/31/07, Update - Photos of the stator cooling mod: Yahoo Photo Album: Vulcan Oil-Cooled Stator Mod
 

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yeah let us know! several of us are on a quest to lessen the stator issue... due to the nature of our charging system, it will burn out.... the question is when. when summer rolls back around i plan to take temp readings of the oil in the stator/flywheel area. i have a theory that there isnt very good heat tranfer from the engine to the water cooling system....leaving alot of heat in the oil... i've already come to the conclusion that the wires that they were using before must have been polyester coated. great chem resistance, but heat is about 275 degs far before it starts to suffer.... and well on a hot day i have a feeling our oil is poking around the 250 mark, and heaven forbid you hit traffic. keep end mind that the stator produces its own heat too, so cooling it with 250 deg oil may not be doing much cooling.....but like i said, its my theory.... i will better know this upcomming summer.

plus then i will get to beat up my frankenstator....
 

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just curious where did u plug up the oil pressure gauge at... when i convert my gagues to digital, i want to monitor that. is it in a rideable location, or just temparary?
 

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Discussion Starter #6
just curious where did u plug up the oil pressure gauge at... when i convert my gagues to digital, i want to monitor that. is it in a rideable location, or just temparary?
I used a shop oil pressure tester which screws into the hole beside the oil filter where the stock pressure switch is installed. When I started the engine for the first time, I wanted to make sure the bearings and lifters were getting sufficient oil.

If you have an aftermarket gauge set, that's where you'd want to plug the sensor in, or route the oil tube from. There's lots of space there.
 

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Discussion Starter #7 (Edited)
Okay! On Saturday I got the bike on the road and had a great little ride in the hills. Everything seems fine; no noise from the lifters and it runs just like it did before taking it apart. I heard a little popping in deceleration - probably from an exhaust leak. Haven't ridden since then due to rain and work schedule.

I posted a link to pictures of the work above in the original message.

Is there a way to tell if this mod is helping? If I get more than 8K miles before another ruined stator, then I'm happy. I plan to take the timing cover off every few months and inspect the stator coils for gummy oil residue. Both failed stators have had a lot of build-up.

Any thoughts?

Has anyone tested their oil pressure at 4K RPM? Mine is about 70 psi - well above the manual spec. I didn't test it before this mod, but it couldn't cause an increase. I was worried about a decrease, but I used 1/8" copper tubing and it doen't seem to be robbing an appreciable amount of oil volume.
 

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it could cause an increase if it is restricting the oil flow, which may be possiable....if its more then 10-20% above spec then i would be worried, otherwise, you are fine... also keep in mind oil weight can cause difference in pressure as well as oil temp....
 

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Drive less, ride more...
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Hey, Darrelc5...

Just out of curiosity, what kind (petro-based, or synthetic) and what brand of oil are you using in your bike engine? And how often--in miles, and/or time--are you changing the oil?

Also: at what mileage (approx) did you relocate your r/r? When the stator failed the 2nd time--did it take the r/r with it?

Thanks!...
 

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Discussion Starter #10
I'm using the Shell Rotella T 15W-40 and I change it about every 5-6K miles.

The R/R was relocated when I replaced it at about 15K. I believe the first one is actually okay because I tested it incorrectly. With two different meters, I cannot get a continuity reading between the control line and the ground into the R/R. Oh well.
 

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Darrell...

When you swapped out your 1st bad stator, did you put in another Kaw unit, or did you go with someone else? For the 2nd replacement--who did you go with, this time (e.g., Ricks)?

Is your newest r/r a Kaw unit--or someone else's?

Also: I'm just thinking out loud here, but clean oil (with working additives) really shouldn't gum up anything. Do you think that, if your (our?) stators are collecting a lot of oil residue/gum, that the oil may need changing more often? I'll be the first to admit that the Shell Rotella T is good stuff, but maybe those bad stators are trying to tell us something here....
 

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Shell Rotella is for Diesel motors, May not like our stators.
Just something to think about.
 

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Discussion Starter #13 (Edited)
To answer your question about the replacement stators, the first replacement was some cheap unit from the local (non-Kawa) bike shop. I didn't really know about the propensity for this failure then, so I didn't take the replacement too seriously. The second replacement unit is from Rick's, who I called and talked to. Like Jon (93VN750) said, the guy Rick really sounds like he knows the issues and has tried to address them with his replacement stator. I have seen stators on Ebay for cheap, and I could have pursued a warranty replacement of my first replacement unit, but the change-out is such a chore, I didn't want to take any chances. The Rick's stator uses good enameled magnet wire and a THIN coating of epoxy for maximum heat transfer. Also the leads have high-temp insulation and are of heavier gauge.

I don't know about the Kawasaki stator because I threw it away when I removed it the first go-around and didn't examine it too closely. Someone else on here has said it's of pretty high quality.

Are you going to change yours?

I don't know about the issues with oil. I have wondered if the Rotella T is a problem. I only had about 3K miles on that oil change before the second failure, which doesn't seem significant. I read somewhere about the effect of the hot stator windings on motor oil and that it causes the oil to "coke" onto the windings, thereby further insulating them. Look at the pictuers in the link above - that thick gummy residue isn't deposits from clean oil. The rest of the crankcase was clean as a whistle.

Another thought about oil: doesn't the factory manual recommend change intervals of about 7500 miles? And they're assuming mineral oil, not synthetic.

Does anyone have a junk engine that I can have the timing inspection cover from? I would like to make a lexan window in the timing cover so I can monitor the oil sloshing around on the stator to get an idea of how much flow it's getting.
 

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Does anyone have a junk engine that I can have the timing inspection cover from? I would like to make a lexan window in the timing cover so I can monitor the oil sloshing around on the stator to get an idea of how much flow it's getting.
There's one on eBay HERE. Although it's from a VN700, but I believe it should fit.
It comes with a stator too, but the removable cover isn't included.
 

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Darrel...

I take it that you read about the "coking" effect on the stator from the following link:

http://web.archive.org/web/20050311234613/ourworld.cs.com/moonmist115/statorreplacement.html

My understanding of the 1st two paragraphs in the above link is....

as the carbon builds up on the stator and its windings, this buildup further insulates the stator. Thus, over time proper heat transfer from the stator back to the oil becomes more difficult, and soon the excess heat will cause the stator's winding insulation to break down somewhere, creating a short. Presto!...there's your bad stator.

Is this a decent description of what's killing our stators--or, if not, what (other) part of the stator is getting cooked first, from general overheating?

BTW: your workmanship in the Yahoo pix looks fantastic!!!.....:notworthy
 

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Discussion Starter #16
Thanks for the compliment!

Yes, I think that's what's killing our stators. The oil feeder tube that I installed is meant to keep enough oil running over the stator windings to prevent hotspots and cooking the oil onto it.

Speaking of engine oil, I'm going to post a question over in the Engine forum about losing oil pressure.
 

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as the carbon builds up on the stator and its windings, this buildup further insulates the stator. Thus, over time proper heat transfer from the stator back to the oil becomes more difficult, and soon the excess heat will cause the stator's winding insulation to break down somewhere, creating a short. Presto!...there's your bad stator.
from what i was able to tell when i disected my burnt up stator was that yes, there was a black residue, but i have a feeling that it is moreso the insualation of the magnet wire burnt off.... the wire is just barely up to spec, so when you hit hot weather, or an unexpected electrical issue, it over heats the insulation, causing it to crack... this then creates a short which creates a runaway effect. the coils get even hotter cause of the short, burning off more insulation untill the oil starts to burn on the stator.... the epoxy that covered my oem unit was in fine condition (a brownish color) it was the wire insulation itself that suffered.

Right now i am running my theory, i rebuilt a stator, kinda like what rick sells. I used higher grade wire, and better epoxy. But unlike rick, i also used a thicker grade of wire, and a new winding method used in hobby motors to get maximum power. havent had a chance to run output test, but i know the idle voltage is solved...

next up on the list of mods, is a complete replacement that should make this issue a mute one.... well about as mute as replacing worn lifters :D
 

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from what i was able to tell when i disected my burnt up stator was that yes, there was a black residue, but i have a feeling that it is moreso the insualation of the magnet wire burnt off.... the wire is just barely up to spec, so when you hit hot weather, or an unexpected electrical issue, it over heats the insulation, causing it to crack... this then creates a short which creates a runaway effect. the coils get even hotter cause of the short, burning off more insulation untill the oil starts to burn on the stator.... the epoxy that covered my oem unit was in fine condition (a brownish color) it was the wire insulation itself that suffered.

Right now i am running my theory, i rebuilt a stator, kinda like what rick sells. I used higher grade wire, and better epoxy. But unlike rick, i also used a thicker grade of wire, and a new winding method used in hobby motors to get maximum power. havent had a chance to run output test, but i know the idle voltage is solved...

next up on the list of mods, is a complete replacement that should make this issue a mute one.... well about as mute as replacing worn lifters :D
Would it not help to fit a main light switch to reduce the load on the stator? Surely the less currrent draw on the stator would give it an easier life?
 

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Would it not help to fit a main light switch to reduce the load on the stator? Surely the less currrent draw on the stator would give it an easier life?
No. And the stator output is constant regardless of use.

You wait two months and your first post is on a 8 year old thread?

Please post an introduction in the newbie forum...
 

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