Long story short Hubster.

Against my better judgement, I loaned out my ZX-6R to a buddy and within about 20 minutes he had overrevved it and blown the AC generator stator coils out, bike died and had to be towed home.

I'm getting about 12-18 VAC at 4000 rpm, book specs calls for 53 VAC at 4000 rpm.

It has to be either shorted stator coils or the permanent magnets in the rotor have lost their field magnetism.

I have ordered and received the new stator and am going to put it in next week sometime and see what I have.

Have you ever seen rotor magnets lose their ooomph or is the stator the weak link here?

* Last updated by: Kruz on 10/8/2024 @ 8:12 PM *

Probably the stator wires. Once removed, you'll see black coil windings, and the rest will be copper in color. Magnets are pretty robust and hardly breakdown... my experience. Pretty much shows output on the test, so my guess are the coil windings.

Charge that battery up while in limbo.

Can't blame the buddy. Just a bad run on the stator. Check for loose magnets. Just pulled a rotor off my nephew's HD shovel and found a loose magnet block. For whatever reason I removed it, it was not the OEM year for it. Took the mighty Amazing Goop Glue and glued it back on. Will last the oil and heat... ask me how I know.

If say the stator looks unburned at those cores, then check the magnets with a metal washer, nail, to see if one block is weak to the pull off.

Ok good information, thanks Hubster, my guess was burned stator windings (shorted) when I saw the low AC output at 4000 rpm. Book calls out the winding resistance between the three phases but the values are so low, almost 0 ohms, that my multimeter just showed 0 ohms. The new stator windings are reading the same 0 ohm values as the original across the three phases, so my guess is my multimeter is not accurate when reading very low ohmic values. When I pop the gen cover, it's going to be an oily mess correct? I ordered a new cover gasket but will try reusing the rubber block where the stator wires pass through the cover. Any recommended gasket sealant, high temp silicone RTV, Pliobond etc.?

Last time I loaned the ZX-6R out it came back overheated with a blown battery and regulator, kid overrevved it. I've ridden the bike since purchased new waaaay back in 2009, so 15 years with no issues but I stay well clear of the redline. I warned this guy to keep rpm at or below 15,000 rpm or it could blow the regulator and he promptly took it it to 16,500. DON'T LOAN OUT YOUR BIKES!!

John

* Last updated by: Kruz on 10/9/2024 @ 12:38 PM *

Ah, the continuous 'don't loan...' syndrome/horror stories. You know they will twist it up because it's not theirs. Anyway, take a single wire to the ohmmeter and see if going to ground at the stator housing, should show 0. Especially do it to all 3 yellow outputs. This shows zero ground of the 3 yellows.

The one loop might show ground of the burnt stator wire. So ground to the engine or frame, stab a wire. See if this moves the meter. Probably need a fresh 9v for the meter.

Yes, oil will pour out on the side stand/using a center stand. More lean the right handlebar on the garage wall. Place in gear. I think the stator is inside the dyno cover so no need to remove rotor. Look for out of round dyno cover placement. Meaning, are the dowel pins showing a straight tube diameter? Maybe tagged the bottom of the dyno cover and moved the pins to an S-bend.

Install gaskets dry. Remove any debris that could cause a hydraulic leak if gasket material is left behind. The good shit is GM's 'Mr. Goodwrench intake manifold sealer' for the wire leads out. Any GM dealer parts dept. It's in a black tube. Kind of around 12 bucks around here. Just used some dabs to set the paper gasket on the HD the other day.

* Last updated by: Hub on 10/9/2024 @ 5:46 PM *

Good stuff Hub, Ill try the Mr Goodwrench product....

Hubster are these special cut bolts necessary to guide the stator cover on straight onto the rotor magnets?
Saw this on another forum, makes a certain amount of sense.

John

* Last updated by: Kruz on 10/10/2024 @ 6:56 PM *

The dyno cover kind of self centers with the dowels. That stud idea is pretty much overkill LOL. On the other hand, that scrub down [if any] would come in handy then. So look for scuff marks, the dowel's straight integrity and all that.

Ok thanks Hub...

Old thread Hub, long story short the ZX-6R has been out of action since last August when I loaned it out and it came back broken, first it was too hot to work in the garage then fall and winter showed up and I was too busy with other projects so the bike sat in the corner gathering dust until this morning when I decided it was now or never. Lo and behold we were right, stator coils are fried, what happened Hubster? Does this take out the regulator/rectifier, that's my concern now as the first thing I tried was a new R/R before I realized it was the stator coils that had fried?

* Last updated by: Kruz on 4/1/2025 @ 9:22 PM *

Hubster I need a decode of Kawi's manual talk from the Xpert , they want sealant only on the crankcase mating surface and only in the areas shown by the hash marks?

Looks like a block of 5 coil windings took the heat. So say 15 blocks all together equals 15v. The output is 10v say. Each block is either N and the next one is S then alternates to make AC.

For next time:
12.8v or higher off the charger.
12.8v with key on only. No drop in volts shows it has reserve.
11.1v with starter motor turning. Shows battery load drop around that voltage reading.
12.8v shows the recovery volts in an instant once engine starts.
14.4v is the immediate volts change with engine starting to idle.

Above shows perfect scenario showing battery being good. Battery recovery shows a well charged battery with plenty of reserve back to recovery. Shows the stator output is at normal range, but can show as high as 14.7v. And shows VR can bleed off stator output being normal and can be reused, is within spec, etc., not needing new with a new stator.

Now will show the 3 components of the charging loop and can pinpoint who in the loop has failed.

Battery: After the current draw via starter motor draw shows 12.1v or lower, relates to a bad battery in poor recovery mode.

Stator: Will remain at 12.8v when idling or revving engine. This points to stator loops burned out and can no longer produce AC at its peak output.

VR: Will show full current output of say 15v of stator output, but cannot regulate the range of 14.4v.

So all you need is a voltmeter on the battery and watch for said numbers above to determine who in the loop shows bad numbered output readings.

I use GM's Mr. Goodwrench intake manifold sealer. Maybe 12-14 dollars a tube vs. OEM brand. Did a lot of intake manifold leaks working for a Chevy dealer. Paper gaskets for the head's coolant, then a bead of sealer across the engine block's horizontal ends. Never had a comeback sold me on the stuff.

The hash marks are used for the case splits, having an oil path at the case halves splits. Another little path is the rubber boot (lead grommet) with the 3 wires going thru it. That lays in a U kind of trough, where the rubber shrinks and/or loses memory down the road. That abstract reads the one hash side is the lead grommet side, and case half the other hash side. I'm saying use sealer laying down the grommet into the stator cover horseshoe area for the grommet.

Where sealer is on the hash areas metal side, place gasket into the dowel's side, being you have one dowel in the cover, the other in the engine case. Which ever is easier to pull out, lay the gasket on the dowel side which steady's the gasket.

Use a new single edge razor and do not dig into the machined sided case halves and cover. Has to be gasket free down to showing metal only. Any remaining gasket material is a hydraulic path out from those rises leftover.

Scraping gaskets off is like an art. Scrape with old stator in but do not install the new windings and possible nick it. A 45° angle for the bulk of the scrape, and 90° straight up for the stubborn areas. Gouging is too deep and creates a path. Slow and steady eliminates the nicks. The Abstract says to use a new gasket and says nothing about sealing the gasket somewhere. So gasket goes on dry.

Looks like a 5mm hex and a 40 torx. Torque for sure.

* Last updated by: Hub on 4/2/2025 @ 12:21 AM *

Thanks Hubster, YOU ARE THE MAN!!

I ended up using the silicone sealant on the engine case side and rubber lead grommet to act as glue to hold the new gasket in position as I stabbed the generator cover back on. Ops check was good, no oil leaks and voltage was at 14.75 VDC, so new regulator/rectifier was fine. Buttoning it back up now, thanks Hubster...

* Last updated by: Kruz on 4/3/2025 @ 7:19 AM *

ZX-6R back in action Hubinator:

Been getting ready for trackday this weekend. Haven't been around prepping anshit.

After 8 month of collecting dust in the corner of my garage I'd almost forgotten how good the little ZX-6R is Hub, 16 years old but still a lot of fun!

Well, I think this one was a 2008 or '07 600cc kawi. Starts like like right now, meaning, fast. Kid was 5th fastest at the trackday meet today. I think it had a cam, was timed, and power commander'd. Thing is quick. Idles semi-mean sounding. Thing is bulletproof with all those trackday hours on it.

Yep, nothing wrong with the older bikes, analog and all, simple to work on, no computers to deal with.