Symptoms of Regulator / Rectifier Failure??

Discussion in 'Dakar champion (950/990)' started by NeptuneTriton, Oct 19, 2015.

  1. NeptuneTriton

    NeptuneTriton Been here awhile

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    Hey guys, can you help me troubleshoot a potential Regulator Rectifier issue? I've read the various threads on different ways of replacing them, benefits of using MOSFET vs. the OEM thyristor based shunt regulator rectifier, etc. But most of these threads pick up after the R/R as already failed or as part of preventative maintenance.


    Which brings me to my question....how do you know your regulator / rectifier is dying? Do they go out all at once or do they fail incrementally?

    Here are the details of my situation:

    Bike: 2013 KTM 990 Baja
    Mileage: 26,000
    Battery type: OEM Yuasa

    Symptoms:

    A couple months ago, the bike was beginning to get harder to start. I noticed it cranking a little slower and taking 2 or 3 hits of the starter to turn the bike over, which is unusual as it always fired up with one touch of the starter. Attaching a voltmeter to the battery leads, it looked like the battery was sitting at 11.8v with the ignition key turned on. During the start sequence I noticed it dips between 10.8-11.6v. I checked all fuses, and made sure the battery cables were tight and not corroded. Also tried charging the battery on a Norco charger and that helped, but only for a day.

    So, I went ahead and replaced the battery with another OEM Yuasa. Much faster starting and the bike sat at 12.0v+ with the ignition key on. In addition, at above 4,000rpm the voltage would read 13.8-14.0 pretty much all the time.

    Several weeks later, the same problems are back....sluggish starting, below 11.7v in the morning, etc. Yesterday on a two hour ride home at 70mph, I noticed the voltmeter had dropped to 13.0v and then seemed to be hunting between 13.0-13.5 then back down to 13.0

    So, that leads me to think my R/R is potentially malfunctioning. If I'm right, does anyone have some updated product/part recommendations for a plug and play solution? I was looking at this aftermarket upgrade....anyone have any reviews or experience?

    Rick's Hotshot MOSFET Regulator rectifier
    http://ricksmotorsportelectrics.com/part/10-013H

    71p1-cJN-jL._SL1200_.jpg
    #1
  2. DirtyADV

    DirtyADV Long timer

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    Not had any failures myself but think if it fails it would cook the battery putting out to high voltage?

    Hopefully someone can correct me if Im wrong.

    Might have been a bad battery to start with?

    /Johan
    #2
  3. speedy 1

    speedy 1 Wizard

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    your on the right track
    when the battery is low they will have starting troubles
    the regulator can fail to keep the battery topped up
    get the upgrade and throw the old one in a bin for a spare

    mine failed slowly
    the symptoms were the same as yours
    new battery couldn't keep a charge
    required a battery tender when parked for the evening
    #3
  4. SpeedyR

    SpeedyR SE in the SE

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    I haven't had the issue but from what I recall it seems when they fail they go too high on the voltage and cook the battery (I have heard you can hear a whistling as they battery fluid is boiling off and escaping the battery). so you replace the VRR and the battery. I don't know if there's another way of testing the VRR.

    I bought the LakeMonster relocation kit and will install it in the next few weeks when I tear into the bike again, that's a good start to keep from cooking the VRR in it's OE position.

    BTW on my bike when it was getting hard to start when it was cold, but started and ran fine when warmed up, my valves were getting out of spec. it got to the point that on my trip to CO a month or two ago, I stopped the bike on a pass to play with the jetting and never could get the bike to start back up again, even after coming back to GA and putting my original jetting back in the bike. adjusted the valves and it fires up immediately hot or cold. YMMV.
    #4
  5. MortimerSickle

    MortimerSickle Semi-Adventurer

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    I have not had a problem on the KTM, but I did manage through my own stupidity to ruin a VR on a Honda.

    It showed no symptoms at all until the engine died at highway speed. I soon figured out that not only was it not charging the battery, but it was not making any electricity at all.

    The bike started just fine at home, then ran for many miles before the battery went flat. At that point everything died, and no more juice was to be had.
    #5
  6. KTMSER

    KTMSER Big bike friendly

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    I have only had one fail to to low voltage, the other ones all over charged and cooked the battery.. You should be seeing 14. to 14.5 I would stay away from the kit you linked..
    Here is the one you need if you go with the Mosfet.. http://www.roadstercycle.com/

    He has several ways of wiring them, on down the page he has wiring made up that you just cut and crimp.. I would and have gone the route he recommends, that is running the charging wires right to the battery instead of charging thru the stock wiring..
    #6
  7. kennyh

    kennyh Been here awhile

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    Timely post. I think mine is failing to return consistent voltage to the battery on my se. Ran heated gear for a while yesterday and the battery went flat in about 90 miles. First time I've had that problem. Disconnected the gear and it charged back up over the next few miles. Put a volt meter on it tonight and it shows decent running voltage (13.4 to 14.5) most of the time but occasionally drops in to the 12 volt range. Don't hear the whining or see any spikes like some have reported. 47k in the stock location. Can't complain I suppose.
    #7
  8. gefr

    gefr Life is a trip

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    The R/Rs usually fail in hot environment. The heat the motor produces cooks them. They also transform surplus electricity to heat, so heated clothing is not loading the R/R, but relieving it. The usual failure R/Rs get is they burn, creating a blister at their back, where there is resin. On the SE moving it to a cooler place helps a lot. Shindengen FH020 is my choice.
    Cheers
    #8
  9. SE Steve

    SE Steve Been here awhile

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    On my SE the regulater rectifier went bad it was over charging the battery. 3 of them I couldn't figure out what was going on. I was in a trip and it would bearly start took it to a shop they checked the battery and voltage while it was running everything checked out. I was at home replaced the battery again was checking the voltage it was all good. Keep the bike running decided to check it again as the bike warmed up. Voltage started at 15 and as the bike got hotter the volts went up to 19.
    I replaced mine with the ricks haven't had a problem since and its in the stock location.
    #9
  10. Kiwi Pete

    Kiwi Pete Adventurer

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    My reg/rec story...

    My 950 started blowing bulbs
    I kept replacing them
    Then it started blowing the fuel pump fuse (I was using a non-KTM fuel pump)
    After inspecting the entire wiring loom for a short...
    I replaced the fuel pump (with a KTM one)
    It blew some more bulbs...
    which I duly replaced
    Then on my next long ride, after about an hour, I could hear this high pitched noise
    The noise was following me
    I stopped the bike, the noise kept going
    There was a pungent smell
    The noise and smell were the battery slowly boiling itself to an early death
    I started back up and continued my ride (I wouldn't recommend this but I was desperate and pissed off)...
    Which luckily was to a KTM dealer where I was due to test ride an 1190
    The bike died right outside the dealership
    Yes they had a replacement battery and reg/rec in stock - no, they weren't interested in taking my bike as a trade in...
    #10
  11. roookie1

    roookie1 Been here awhile

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    Mine died slowly like Yours. Replaced with a Mosfet from a Honda cbr 600 2007 onwards bought used on Ebay, for a song...It fits the stock bracket..
    #11
  12. NeptuneTriton

    NeptuneTriton Been here awhile

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    Thanks everyone for the advice and background history on how your R/Rs went tits up. Looks like the failures can be both instantaneous, resulting in rapid overcharging OR a slow dying death, typically characterised by undercharging, low voltage, and slow starting.

    Another good observation. I'm due for a valve check in about 1,000 miles, so I'll keep in mind to pay attention for increased/decreased starting effort before and after I get that done.
    #12
  13. NeptuneTriton

    NeptuneTriton Been here awhile

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    Ok, now that I've decided to replace the R/R...which direction do I go? I'm not an electrical clutz, but I'm not a whiz kid by any means.



    The Roadster Cycle kits look top notch, but I was hoping for more of a plug-and-play solution...it appears you have to essentially create your own wiring harness with soldering, splicing, shrink wrapping, and connectors. It's doable, but since I'm a novice I find it a little bit intimidating, unless I'm overthinking it.....



    It appears there is a new R/R option on the market from Shindengen, a series-style, that is supposed to be better than the current MOSFET offerings:

    "A newly designed, open-type rectifier disconnects the magneto when it is not generating electricity. Plus, the magneto is more efficient than that of the previous V-Strom 1000. These two advances reduce mechanical losses, resulting in stronger torque at low and mid-range engine speeds. I believe this could be one of the two 50A Series Regulators that Shindengen listed as "in development"."

    http://www.triumphrat.net/speed-tri...iagnostics-rectifier-regulator-upgrade-2.html

    Attached Files:

    #13
  14. keener

    keener Speed changes you.

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    Not all charging issues are because of a bad RR. Stock RR can work fine for a long time. Mine has 95,000km on it with no issues.

    Stator could be at fault too. Worth checking before installing a new RR. It can be tested using an ohm meter for shorts between wires or to ground. And an AC voltmeter to see if all three yellow wires are sending similar voltage to RR. Lots of info around on how to test a motorcycle stator.
    #14
  15. tasslehawf

    tasslehawf Been here awhile

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    I had an issue with my reg/rec cooking my battery, but it only happen one day and I haven't had an issue since.
    #15
  16. DirtyADV

    DirtyADV Long timer

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    Never heard of a bike that new that have stator problems but if you are due for an oil change and checking valves maybe dump oil into a suitable clear container and see if there are any signs of copper bits in the oil.

    Earlier models had problems with some bolts backing out and chewing up the stator.

    /Johan
    #16
  17. gefr

    gefr Life is a trip

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    So it seems the series SH775 is working cooler and producing up to 35A with proper cooling. Since the max output is going to be needed in cold weather using warming clothing, there shouldn't be a problem getting 27A at 14V = 378W.
    So the question rises: why do shunt R/Rs still exist?
    Why aren't they obsolete?
    Cheers
    #17
  18. keener

    keener Speed changes you.

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    Exactly my question too! Brand new bikes are still coming out with shunt RR, why?!


    Regarding the stator: it can look just fine but have one of the three wires shorten to ground or other wires inside the spool. Can't tell without an ohm meter. Its an easy test.
    #18
  19. NeptuneTriton

    NeptuneTriton Been here awhile

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    I totally agree. IMHO, there's no reason KTM should be using the outdated shunt R/R's anymore, they are indeed obsolete. The Japanese bikes have been shipping with MOSFET R/Rs for years and now the new Suzukis are shipping with the next generation series R/R's from Shindengen.
    #19
  20. Rharr

    Rharr Been here awhile

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    Cheap and easy to make. Probably have a ware house full of them they need to unload.

    Go Series, can't go wrong.

    I have a very very meticulous, anal, over analyzing, electrical/computer engineer friend who basically did a thesis for fun on RR's and found the Series system best. At the time of his research he was recommending the compu fire stuff because it was functioning just like the new vstrom rr. Turning legs of the stator on and off as needed, which made air cooled bikes run cooler (his test bike) and extended the life of the stator because now the wires weren't forced to constantly produce juice.

    Just looking at the post and I noticed my buddy's information is being reference. (the gs resources source)
    #20