Mon, 11 Jan 1999 02:36:09 +0200
- Message No. 4685
From: Tommi Miettunen
Subject: XRV Engine problems
>Voltage regulator: that4s it! I didn't know the name of it in english. My
>honda dealer changed it and it was very expansive (Eur179.57 or 36000$00).
>But the problem is still there. I'm damned with those guys.
>
>Jorge Pereira
Hi Jorge!
The way to correct these symptoms on your bike seems to be indeed very
simple one (electrical problem) but finding it may be hard & needs more
accurate searching methods to avoid false diagnoses... I am not an AT owner
at least yet (so don't take my opinions for granted!) but some of those
symptoms of yours seem quite similar of those I've had on my previous bikes
and on my -88 Honda Transalp which shouldn't be so much different from the
AT. At least I hope I can ease your situation a bit.
To my opinion the way your bike's lights are winding down when accelerating
is indeed related to the generator (but the does the headlight actually get
better when using signal lights and when the signal is lit! or is it other
way around as it should be?) The generator itself may be working fine but
somehow the charge gets lost in the way to the battery and finally to all
other electrical systems. A general cause to this might be loose or
corroded couplings & connectors.
You mentioned a replaced voltage regulator so it can't be the problem but
please double check the connectors if originally done by someone else (a
regulator fault to my opinion burns up your bike a bit as the voltage gets
too HIGH for all the lights on your bike. So when accelerating the lights
should get brighter & brighter until they finally break down one after
another).
You also changed a new battery which should be fine but needs further
checking because the battery is ALSO a voltage regulating unit on your
bike. The easiest way to do this along checking the electrolyte levels
inside the battery is to get a volt meter (I prefer digital ones which can
be found low priced in almost every shop selling car spare parts and
accessories). To certify a good battery & generator & voltage regulator you
may have to strip off your bike a bit to expose battery terminals & attach
a voltmeter to them. You should get at least 2 separate measurements to be
sure this part of electrical system is in good shape. The no 1. measurement
is to be taken engine off and in a situation it has been out of use over
night for example. The volt meter should read close to 12 volts or better
for a good battery. If the bike starts up good this measurement is really
not necessary but is still a good reference. Anything under 10 volts after
one night standing and I would say there is something wrong with the battery.
Ok, if the battery is fine start up the bike and measure the charging
voltage now. It should read something between 13-15 volts and changes
upwards gradually when the bike warms up and the battery gets charged.
Anything over 15 volts should be considered a bad voltage regulator unit
but you would have found it out by other means as I mentioned earlier.
It seems your bike is lacking power so it can be some of these units or the
bike's wire couplers/connectors and switches. Next thing to measure are the
couplers and the best way to do this is to disconnect the headlight plug
(or some other device at the end of the electrical chain) and measure the
voltage from the plug. You should get the same results (0.1 volt drop may
be expected) as when measuring directly from the battery.
If any of these measurements show irregularities you should disconnect &
reconnect all the couplers between the battery and the trouble maker & try
again. Corroded connectors usally get back to work only by doing this but
may be also be cleaned with some alcohol, thinner etc. To ensure
connectivity you can also use some abrasive methods (lightly) on the
connectors. A fine way to protect and make work connectors/switches is to
apply some protective oil to them (just wipe off with some cloth on which
the stuff is first applied). The best stuff for both cleaning/protection is
sold in experticed electric shops dealing with basic parts such as
resistors etc for hobby and professionals. It can be a bit expensive stuff
but it is GOOD. If not available a good substitute is GUNOIL!
So all the switches/couplers in the bike may be working correctly when
measured but when get corroded they get also resistive and actually lower
the voltage getting through them when LOADING the circuits heavily as in
normal use (a good faul generator of this type would be the ignition switch
as it performs a shitload of work every time you use it. It connects
electricity on/off on the WHOLE bike. It doesn't like a bit of bad
weather/dust etc. Luckily it's very well protected against any type of
corrosion but is not 100% sure thing as nothing else on the bike :)
A good rule of thumb when having electric broblems which accure, dissappear
and reaccure strangely IS: Almost every time there is some not 100%
functional switch, relay or a stationary coupler (not as obvious as the
first 2) in the way. Some of those must be replaced, but almost every one
(ignition switch is maybe the hardest) is disassembable and maintainable by
anyone who knows what to do or is even interested to try something like
that at home (just scramble, clean & unscramble the opposite way).
Stationary electrical parts such as CDI units, voltage regulators etc. are
rare to contain faults since there is NO moving parts inside the unit
causing wear & tear. Only thing to cause faults IN these units is
overloading and burning up the unit which might also be seen visually. BUT
these units DO NOT work anymore normally in any way if they burn up (I
would replace burned ones but NOT before checking further...)
The number 2 fault type in the stationary units would be a loose connector
fault caused by vibration. And when loosing it the damage is often on the
units circuit board.
Now you suspected there might be something wrong with your CDI units as
well. I doubt it but here is how you can find it out easily by yourself:
The CDI units are closely related to the operation of the engine since they
are only used to apply a signal to the spark plugs at the right time, and
have nothing to do with the bike's lights for example (please correct me if
not right because I AM NOT an AT expert!) So in my Transalp there is two
CDI units parallel directly behind the fuel tank & the drivers seat. The
one in the right is controlling the real cylinder by twin spark plugs as
the left one is in charge of the front cylinder. (Very odd configuration if
you want to ensure the spark getting in each cylinder at maximum
reliability) I suspect this is also the way things are on AT!
I had a fault on the one unit which I also fixed at home. The symptoms
appeared occasionally & the top speed reduced to only 90km/h! regardless of
the gear used. The sound of the engine was also bizarre as if it was choked
in some way. The tachometer also went dead in the same moment. Now the
electrical shematic of the bike (try to get one if not already have) proved
there was nothing happening in the box in the right because the signal from
it was also passed to the tachometer. So I did a simple thing to verify &
isolate the fault: I switched the units (the left one to the right & vice
versa). Everything was smooth again (for a while). Next time the problem
reappeared there was nothing wrong with the tachometer so I knew which unit
it was (the odd engine behaviour was because the other cylinder was dead
since there was no spark to the plugs)
Now this kind of CDI fault seems to be quite common amongst bikers and is
caused by vibration (similar unit for exapmle can be found in a Honda four
wheel ATV vehicle. My father had also this fault in his ATV and it was
fixed so I have seen these quite a bit). Anyone being sure having faulty
CDI unit DO NOT buy a new one before attempting to repair the old one! Its
VERY easy and I can tell you how to do it... (I've seen this fixing being
done also on the net but I just can't remember where I saw the thing, DAMN :(
Your engine not running over 6000rpm:s is another thing. I cannot say what
causes it but try this: My Transalp was also at one point lacking top speed
some 30km/h and I checked & disassemled the carburators, electricity the
whole thing many times over. Nothing was found... HEHE! I was a second away
from givin' the bike some nasty kick in the ass, but instead I tried the
one thing more... I changed the spark plugs (heh) and everything was normal
again!!! These replaced AGK:s had run just barely over 10,000 km's so I had
no way of suspecting them because normally I drive a whole lot further with
one set.
That's all folks by now, feel free to knock me down if I'm done something
wrong here.
Greetings: One devoted biker & an AT lover (without one!)
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