Typical noise and case of a disintegrated rotor

Today i was out with the blue A1, that was about the plan for it,...but after 50 km´s, i felt something is wrong: Left side typical noise! Must be the rotor...I´ve stoped, let it idle, sure, typical rotor or freewheel noise.Then stopped the engine. While pushing the starter. knob,.Uhohh, starter turns hardly slow, nearly discharged battery. So without any lights on  fastly return to my home base
So, first, I measured the voltage and charge: Only 12.4 volts on-board voltage, even when accelerating, no more than 12.5...and with the lights on, only 12 volts...plus the noise...

So, I propped the bike up against the wall on the right side (I have a special rubber stopper for the handlebars on the right, so nothing can happen).
Then I removed the clutch and alternator covers, and lo and behold: "a little" loose in the rotor...or a little more    ...but the 3 8mm bolts to fix the rotor to the freewheel-cluth have been very tight, no loose,..but the little rod between the was broken..(.all in all a typical damage, in the last  more than 4 decades, i´ve had this issue nearly often on all my Kawasakis, only my Z1B havn´t had this in 20 years of hard using..)




Then I pulled the rotor off and separated it from the freewheel, which usually looked pretty bad. A completely disintegrated rotor is something we all know all too well. Luckily, I had a spare part, so I put everything back together, and the engine is running smoothly again (at least as far as the alternator is concerned )

     


...but still no better charge. Something killed this damage, probably the diode rectifier, because I noticed that it got quite hot immediately, but that's another story
 
 

It could have been much worse. In 78 I had charging issues that got worse and worse. Had to charge the battery every night just so I could go to work and sometimes I had to use the kick starter to get home. One day I was on my way home and the noise turned into a grinding then a rrrrrrr clunk and a frozen engine. I pushed the bike home to take off the cover. It wouldn't budge so I let it cool off. Came back and it took all my wood chisels around the case little by little to pry it off. After an hour of doing this I finally got it off. CARNAGE  The rotor was coming apart and destroyed the stater. Now I needed both and a voltage regulator too. Being young and broke I would charge the bike everywhere I went. I finally found used parts and got it on the road again but the regulator still didn't work. I got three mini regulators and wired them in for the lights, coils and battery. It still overcharged a little and I rode the bike until the wreck in 86. 

Well that sucks Joe, is the stator damaged ?

@ Steve:The trick is to always pay attention to the noises and then check under the alternator cover in time, then the damage will usually not be that severe.

@ Wookie:
I have not noticed any mechnical damage there, But I have to measure the resistant of stator windings...I'm guessing it's the regulator or rectifier,..but we will see, good is for first, that the mechanical problem is solved, it makes me always sick, when my engine have some mechanical problems
 
 

Hi Joe, and nice to see that you have a good ear. So many people do not listen to their bikes or cars when out and about. Good save 

We´ve measured the stator windings today, and everything's as it should be,.... but my first suspicion was confirmed:
The diode rectifier burned out, for whatever reason, parallel to the rotor failure. Luckily, a friend of mine had one lying around, so I installed it, and immediately the charging voltage was back to 13.4-14 volts. So, everything's OK again
 

MFP-Joe post=917703 userid=24810@ Steve:The trick is to always pay attention to the noises and then check under the alternator cover in time, then the damage will usually not be that severe.

@ Wookie:
I have not noticed any mechnical damage there, But I have to measure the resistant of stator windings...I'm guessing it's the regulator or rectifier,..but we will see, good is for first, that the mechanical problem is solved, it makes me always sick, when my engine have some mechanical problems
 
 

That was back when the bike was new and not a lot of them around. A rotor was $300 new and at that time I didn't know they were weak along with the charging system. I was running a 100w pencil high beam and a 55w low beam. My rectifier got toasted later because of this so I used a Yamaha 650 rectifier that is larger and more solid. Still have it. The diodes came un soldered on the old one. Too hot. This is what I was using until I got a late model R/R. Still the charging system is weak. I want a Rick's rotor that puts out 55% more power.
ricksmotorsportelectrics.com/New-Hot-Sho...wasaki-Rotor-41_200H



 

Hi Steve,
Yes, the "light output" was really poor back then. In the late 70s, i´ve had really strain to see enough in front of me at night wen i´ve traveling fast. Plenty of my rotors had given up, but I must say,in my youth, i was also mostly traveling at very high RPM´s and speeds on the way...

But sure, theese original old rotors have always been the weak point on the engine, especially here in germany, cause it was often so, that we run our bikes at high speeds for longer time on the "Autobahn" , ( Highways without any speed limits), and this maybe 20-30 minutes at full acceleration on 135 MPH, that have killed some of them...

BTW: Are now better rotors available?? I´ve just used my last storraged one...
 

kimchella wrote:

Hi Joe, and nice to see that you have a good ear. So many people do not listen to their bikes or cars when out and about. Good save 

Many moons ago, I worked for a major Japanese OEM auto manufacturer, in their quality department, providing after sales support.  We had one particular model, a van, that was designed for Japan, but some product planner dudes decided it would supplement the US fleet and broaden appeal.  Long story short, when this vehicle was subjected to US driving demands, and customer driving habits, it would sometimes overheat.  Dash warning lights would come on, telling the customer to stop driving, but some customers ignored the warnings and kept going.  Sadly, these conditions would lead to vehicle fires; customers would drive the vehicle, clearly overheating, until freeze plugs would pop out of the engine block, and/or, some heater hoses would burst.  Point here, it's always good to pay attention to the signals your vehicle provides.  Be they audible, visual, or some warning light.  .

Nessism,you´re absolutely right with this,..or in short: Every vehicle is so good, as you´re maintened it !
In all the  years ago, i´ve tried to keep my "sensors" sharp, meant. Listen to some unnormal noises, or chassis  / steering reactions, or simple: Does it all feels ok?  And in any case of a doubt, check it!!!
Luck is just an imagination, luck is with the well prepared guys!

Keep on ridin`and have fun!    -So as i:  Í´ve had a good 60 Km ride after my repair with a good chargin electric system, so, my personal Kawasaki sun is shining again

MFP-Joe wrote:

Hi Steve,
Yes, the "light output" was really poor back then. In the late 70s, i´ve had really strain to see enough in front of me at night wen i´ve traveling fast. Plenty of my rotors had given up, but I must say,in my youth, i was also mostly traveling at very high RPM´s and speeds on the way...

But sure, theese original old rotors have always been the weak point on the engine, especially here in germany, cause it was often so, that we run our bikes at high speeds for longer time on the "Autobahn" , ( Highways without any speed limits), and this maybe 20-30 minutes at full acceleration on 135 MPH, that have killed some of them...

BTW: Are now better rotors available?? I´ve just used my last storraged one...


 

Kind of pricey but I'll get one anyway. 

ricksmotorsportelectrics.com/New-Hot-Sho...wasaki-Rotor-41_200H