Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Problem resolved, but what exactly was it ?

Discussion in 'Technical and Troubleshooting Torque' started by коннор, Jan 28, 2015.

  1. Wednesday last week, which was a warm Melbourne day (even at 1800), I ended up filtering pretty much from Warrigal road up the Monash and along Punt road. Unfortunately, when I went to turn from Wellington parade to Brunton avenue, my bike died in the arse. Didn't even have idiot lights. I vaguely recall it feeling, towards the end, a little like it was running low on fuel, despite having a full tank.

    After sitting around for a few hours the lights came back and a bump start did the trick; it's been running fine since and I'm not too worried about it, but I figure it's worth actually diagnosing if only for the practice.

    It's a 1989 VFR750F with a Motocell lithium battery. Otherwise stock for the electrics, as far as I'm aware (only had it the last few years, though). I think the coolant is about due for a change.

    My guess is something was affected by the heat (alternator?) and meant there was no electricity being generated, resulting in the bike running off the battery... until it ran flat (and as it got low the spark suffered, causing abnormal ignition and that 'low fuel' feelin'). After the battery had rested for a bit, there was just enough charge to light things up, but it was well short of the juice needed to turn over. Having cooled down, the other stuff was working again and therefore willing and able to do its job after getting a push.

    Do I sound like I'm on the right track? Am I more or less ignoring something that's screaming threats of earth-shattering kabooms?
  2. It's a Honda, and a VFR to boot; replace the regulator/rectifier and it will love you for the rest of its life, and your battery will heave a sigh of relief too.....
    • Agree Agree x 1
  3. Coil/leads expanding in the heat and loosing connectivity maybe? How old are the HT's?
  4. Definitely sounds electrical. Don't think WombleWomble 's suggestion is the right track though. Loss of idiot lights as part of the symptoms is unlikely HT. I am more inclined to go with your original diagnosis and Hornet's suggestion. Do you have a multimeter, measure the voltage across the battery when the engine is revving it should be 13:8 - 14.5 outside that and it indicates Reg/Rec or Stator.
    • Like Like x 1
  5. Given they had a tendency to die (as I recall?), I assume that's one of the things that has been done for it. Though you do have a point, it may be a more likely candidate than the alternator itself.

    I have been thinking about replacing the ignition coils after a tuning specialist suggested it (since they do age), as I expect they're the originals. Got four of the bloody things, though :eek:.

    I'm not sure what you mean by "HT's". With this bike, I generally assumption that things have not been done unless I know they have -- it had chocolate syrup in it's brake system (some may assert it was brake fluid, but my eyes say otherwise :p).
  6. if you don't know for sure the reg/rec has been replaced, the symptoms you describe are justification enough to replace it (for the first time, or again)
  7. Before I started it, after sitting around for a day or two, battery was just under 13V.

    Idling 1k and change, ~13.55V.
    Revved to 2k, ~13.8V.
    Revved to 3K, 13.5V.

    Yeah, it is looking that way. Given the age, I suppose it's entirely possible it was replaced, but has had a couple of decades to wear out again. At least it's an easy job and a relatively inexpensive part.
    • Like Like x 1
    • Like Like x 2
  8. HT's = High Tension leads AKA the leads that run from the dizzy to the spark plug, looks like I'm on the wrong track anyway based on Chris' comments.
  9. #10 Lionz, Jan 28, 2015
    Last edited: Jan 28, 2015
    Check the voltage across the battery when running to see if it's charging, should be 14+ volts.

    Maybe a reg rectifier and stator check to be on the safe side.

    Edit**Jeeze, where did those other comments suddenly spring from! Chris/Hornet has it covered
  10. Yeah, I'm not up on lithium batteries (what voltages they should hold, etc.), but the running voltages certainly did not look right.

    Might this one be more appropriate for my '89? (Note that the model wasn't sold in the USA that year)

    Aahh. I had a feeling you meant those, but didn't have the name to match, if you know what I mean.
  11. Ah yep sorry didn't pickup on the year. I have one of their replacements for my VFR800 and it has been in over 10 years now without an issue.
  12. As a former battery guy, the Lithium batteries in 12V form are still the same as sealed lead acid batteries used more commonly. They were designed to fit the current purpose and charging rates motorcycles and vehicles used. The technology is within the battery where it contains a chip/board which regulates the charge (to ensure not too much)... basic guide only...

    ... after hearing about a HD dealer in QLD trialing several different brands a year ago I won't be using them until they are more proven in the field (5 bikes caught fire). Lithium is quite an unstable technology (hence why your mobile phone gets hot when you run lots of apps at once).

    Also, charge rates on car/bikes is generally between 13.5V and 14.2V. A standard 12V battery is fully charged at 12.7V and dead flat at 11.9V. You can generally recover a battery that has sat around a while if it is above 10.5V.
    • Informative Informative x 2
  13. Check the cable connection into the battery. I had something similar on an XJ900F in the centre lane of the F3 back to Sydney at night.

    Engine spluttered a bit then the lights and engine just cut out. Got to the road shoulder without getting hit by evening traffic, sat clueless in dark for a bit and everything came back on. At home, found the bolt on the terminal had worked loose and the cable just had intermittent contact.
  14. Hornet is correct, VFRs are know for issues with the regulator/rectifier and the stator. Suggest you go to ozvfr.net see link below:


    There is a current discussion on checking the R/R and stator (link above). Process for testing of the stator is below (taken from the discussion):

    The stator keeps putting out three phase AC power, more revs, more power.
    The regulator/rectifier converts AC to 12 volts DC and gets rid of unused power.
    LED's and HID's use less power, the regulator has to do a lot more work.
    The regulator converts excess power into heat.
    The more heat, the less the regulator will last.
    The best set up would be one where the stator only makes slightly more power then needed, then the regulator wouldn't have to do much work.
    Most people are under the mistaken idea that using LED's and such make it easier on the system, it's the opposite.
    Rev the bike for a couple of minutes and feel the regulator, it will be very hot.
    Check all the connections, specially the stator to regulator plug, this often melts.
    The regulator to battery plug seldom fails, but also needs checking.
    The main harness earth block is another regular fail spot, needs to be untaped and inspected.
    Any of these could kill your battery without it being the regulator or the stator, but if not picked up early enough, it can cook everything.
    Do a check before you buy anything.

    The fault finding diagram says that at 5000RPM you should be getting at least 50v AC output from any 2 wires of the stator, and all 3 phases should be the same.
    Are you sure you are using the multimeter in the correct range? ie 100v (min) AC
    Did you check to see if there is any leakage to earth from the stator windings, ie check resistance to earth from any of the yellow wires. It should be HIGH resistance
    It sounds like the stator is most likely cactus.
    If it is any help, I have an unused 4th gen RR that you can try out once the stator is replaced, but I am not sure if the plug is the same.
    It is possible that all 3 items, stator, RR and battery are stuffed, but if you take the battery off and charge it up and it holds its charge it is OK.

    see attached trouble shooting guide

    Attached Files:

    • Informative Informative x 3
    • Like Like x 1
  15. I've been seeing a lot of complaints / issues lately with bikes running Lithium batteries.
    I'm ex battery industry too and I'm wondering if there's an impedance / charging issue that isn't immediately obvious.
    Sure the books and retailers all say it's fine, but I've seen lots of different makes and models dying with lithium batteries fitted.
    • Agree Agree x 1
    • Informative Informative x 1
  16. Following on from that guys one niggling thought I had was Lithiums have over temperature protection. Hot day, high charge current perhaps the thermal protection would trip. Does anybody know the nature of the thermal protection is it self resetable or a once off?
  17. I would think in the charging circuit it would have a resettable type, and that each cell has a permanent fuse link for major shorts or thermal overload.
  18. I'll put it on my todo list, but, after changing my rotors just now, it'll be going below "replace brake pistons" =\.

    I have only measures DC voltages at the battery (needed to get places yesterday); I haven't gotten as far as checking the AC/stator. The multimeter was definitely in the right range (and the readings I got would've been really screwy had it been set high or low :p).

    I appreciate the offer of the RR, but getting it down to Melbourne and back up might be more trouble than it's worth :).

    I just had a look at my battery's ol' bita paper to see if it mentioned the length of warranty (just in case), and noticed a bit where it says "Lithium... Battery... (12.8V)", then checked it's charging instructions, which only say to worry if it drops below 12.4V after charging. So that sounds like it's actually within spec (bang on, in fact).

    Given that the RR is the most heat sensitive component in the chain and is a known point of failure, it does seem the most likely culprit. The stator may be worth checking, but it is not a priority at this point, especially since I'll be minimising my riding until I get my brakes back to 100%.

    I've heard a lot of newer bikes have fanciness to maximise the life, etc. of lead batteries, and that it doesn't mix so well with lithium. Older bikes, where you basically just have a continuous charge dumped on the battery do not, supposedly, suffer this problem.

    It would be interesting to tally up how many of the problem bikes are recent models and how many are oldies or old tech.
  19. Yes desulphation charges are something specifically targeted at the chemistry of Lead Acid batteries. Lithiums don't like it much. I know some maintenance chargers do this, I wasn't aware of manufacturers building this function into bikes but its possible. It does extend the life of Lead Acids. Two ways of doing it, one is a high float charge of 15.5 - 16 volts. The other is by a pulsed DC which is the more common method.