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About Cooter

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    Local Racer

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  • Location
    New York
  • In My Garage:
    95 ducati monster 900
    96 ducati sssp
    98 vfr

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  1. I'm selling my red 1998 VFR. It's in just shy of immaculate shape, no crash damage just the normal dings on the fairing belly. It's always garaged in a climate controlled space so no rust or sun fade. It's just shy of 30K miles. Recent brakes, chain and sprockets and Pilot Sport tires. The stator and rectifier were replaced 5,000 mile ago. The originals had not failed but charging voltage was lower than optimal so I replaced everything proactively. There was no damage to the wiring harness. The only modifications are the mirrors, replaced the so called "condom mirrors" with the later generation, a one tooth smaller counter shaft sprocket and "Speedo Healer" to correct for gear change and a Two Bros. Silencer. I have all of the original parts including seat cowl and Tool kit. It also comes with the factory service manual. It gets serviced annually with full synthetic. This is an excellent example of a 5th generation VFR that's ready to ride. I will post photos later today. The price is $2,500. Call or text at 917-846-6673. I Will consider delivering in the Tri-State area. Pictures now attached and a correction, the mileage is a tick over 30K but still a fine example of a 5th generation VFR.
  2. Cooter

    Stator Tests

    I said I would report back after I installed the new parts. Just to remind everyone, I was not having problems with the bike staying charged, just lower than spec charging voltage that would drop even lower, into the low 13's, as the rpms rose and was only showing 38 volts output max from the alternator. I also had the original RR. I had no signs of over heated wiring or connectors. I decided that I would go ahead and replace the stator and regulator proactively. My stator looked very similar to Chris' very toastie on the same side as his pictures show but it still tested OK except for low voltage output. After replacing the stator and RR, I am now getting charging voltages in the high 13' to low 14's with little to no drop on rising RPM and output from the stator of 50 volts and up, rising with rpm. I did do a little maintenance on connections but nothing that I would consider an A HA. I now firmly believe that much of the problem with these bikes starts with a failing stator. As the stator begins to fail under heat and load, it appears that the voltage drops and the current rises which then starts playing havoc with the rest of the charging system. I have posted references to this in my previous posts on this topic as well as a post on the general fraility of this type of alternator (stator) design. For those of you having multiple rr failures, I would consider replacing the stator. For the record, my bike is a 98 model with 24,000 miles and no history of electrical problems and hopefully, none in the near future.
  3. Cooter

    Stator Tests

    I've ordered a new stator and RR (OEM from Honda) and am going to wire it all directly to the battery using Weather Pack disconects and No. 10 sxl wire with a dedicated 40 amp fuse holder, I'll dialectric grease all connections and use thermal paste in mounting the regulator. If I end up with the same voltages then I'm going to call it done and carry the old rr under my seat as a back up. I'll report the results when I'm done.
  4. Cooter

    Stator Tests

    I too, haven't heard great things about Electrex and wasn't suggesting their products. After reading your post and having my own issues, I really started digging around to try to learn how exactly the various components of the charging sytem worked. There is a fair amount of information out there (I was searching motorcycle voltage regulator design). The article I quoted was the first explanation that made sense as to why a stator would test OK in one circumstance and not another or in my case why the stator shows low output but continues to function in the system (it is failing slowly). I ran across another tech article from an old bike magazine that said that this type of charging systen design is so flawed (the 2 piece design of a stator mounted off the end of the crank relying on oil for cooling and a seperate rr) that it really can't be expected to last much more than 20,000 mi. It is still in wide use on sportbikes because of it's cheap to produce, light weight and compact. Here's the link www.reptilesmagazine.com/mcn/technical/MCNdec05charging.pdf Don't ask me why it's in a Reptilesmagazine link, the page says it's from Motorcycle Consumer News, ah the mysteries of the internet! Please post your outcome with a Rick's rewind.
  5. Cooter

    Stator Tests

    I started the other thread on 5th gen charging problems a couple of days ago so I'm interested in your results. At first, from your description I would have thought that you had a second bad rr given that your voltage from the stator seems good until it's attached to a load but I found this snippet of information on a BMW site. It originally came from the Electrex site but doesn't seem to be there any longer and coincidentally, refers to VFRs! Anyway, after reading it, I think you should replace your stator and unfortunately, possibly your your rr as well as it appears that a failing stator will take out the regulator. Here's the quote. <<VRF Regulator Rectifier Basics Inside there is a six diode full wave rectifier, and every phase input can be switched to ground through a thyristor. The thyristors are switched by a regulator circuit that measures the DC output voltage. We call this a shunting regulator. It is a very simple system, and doesn't work very efficiently. But it does the job while not dissipating too much heat. That is why most OEM manufacturers still use this setup. First of all the regulator relies on it's heatsink. That in itself is not bad , as long as there is good thermal contact between the diodes and thyristors inside the unit to the housing, and as long as there is a good airflow. Quite often when a regulator/rectifier fails, a new one will fail after a fairly short time. It is a recurring problem (not on all bikes, but has been seen quite often). The stator has 18 poles, 6 per phase. Each pole has (I don't know exactly) about 20 turns of copper wire on it. Between the phase outputs of a delta wound system you will have 120 turns. Because of the hot spot in the engine, the copper winding's insulation starts to fail after some time. Most likely that will be somewhere from one layer of windings to the next layer on a pole. This usually happens only under load and when the unit is hot. Imagine a few of these shorts in between the phase outputs. You will have not 120 turns but say 50 or 60. The complete charging system will still be able to reach 14.4 V DC, it is rated for about 400W. When you have a transformer with only a few thick windings, you will get a low voltage but higher current output. The same happens in the VFR Delta stator. Those 60 turns will give a much lower Vac but a much higher Iac. And diodes in regulator/rectifiers don't like high currents. If they are rated for 35 Amps, as most diodes are in this application, they can handle that whenever they get sufficient cooling. When they run hot, the max current they can handle drops down quite a bit, which makes dissipate even more heat, and finally one of the diodes fails! Electrex stators are wound in star. The total power output is about the same as the original (lower Iac times higher Vac makes about the same... I know this is simplified, there is more to it....). But there are always two phases in between the phase connections. (=240 turns) The Vac is higher, and the Iac is lower. Even if there would be a short in between some layers of turns (I haven't seen that happen) you still wouldn't have the current output of the original stator, which is what destroys regulator diodes. So far this is still unproven, but seems correct. It is difficult to prove, as you need to check the original stator for shorted windings whenever the systems is under load, and very hot. And it doesn't need to do it all the time even! Bikes that have had a few failing RR's stopped frying them after replacing the stator. One last thing: Problem #3:The output of the Voltage Regulator/Rectifier (VRR) is fed through the wiring loom and some sort of junction box to the battery. Make sure you have perfect connections here. I found a number of problems with voltage drops over these lines. Check the fault finding chart on http://www.electrexusa.com. It will guide you through the process. The best thing to do, if you see any voltage drops in between the VRR and battery (we are talking high current here, so any bad connection will give a significant voltage drop) is to feed the output of the VRR straight to the battery terminals using a (good quality) inline fuse.>> Hope this is helpful to everyone.
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