Speedo gone NUTZ!

The other day I ran my battery down. Left the ignition on after working
on it. Dead as a door-nail. Figured I'd just bump start it in the a.m.
cause it was late (and my driveway is sloped nicely). Well, in the
a.m., finally got it bump started after a few failed attempts and it
ran like crap.
Well, CRAP! So, I pushed it back in the garage, put it on the charger
(should have done that the night before) and caged it to work. That
night it ran great! Whew, I feel better now.

So, the next a.m., I jump on the bike, meet up with a buddy from work
and we start off to work. I look down and we're doing 120 MPH! Wow,
must have been a great charge-up of the battery! Hit the strait fast
stuff, now we're doing over 180!!!

Needless to say, my speedo is now indicating ~3X the going rate. I read
the manual and the shop manual and nothing touches this one. Anyone got
any ideas or know how to reset this thing? The dealer said their recourse is to test the sending unit, shorts, etc. I just hate to give it up for a while if there's a magic reset button!


(cross posted on ADV)

Sounds like you got it to read KPH instead of MPH. Push and hold the RESET 2 button for a few seconds and it goes back and forth between the two. Did it myself by accident one day and couldn't believe I was going so fast. Then I looked closer and saw KPH.

mwakey wrote:

Sounds like you got it to read KPH instead of MPH. Push and hold the RESET 2 button for a few seconds and it goes back and forth between the two. Did it myself by accident one day and couldn't believe I was going so fast. Then I looked closer and saw KPH.

Thanks for the reply mwakey! Nope, I wish it was that simple. That was the first thing I checked. Plus, that would be a factor of X1.25, not X3

I tried unplugging the neg. cable from the battery for an hour, thinking it would reset it, but no go. The other pisser is it's also recording mileage at a rate of X3. I put on 240 miles in 2 days when it was actually only 80.

Have you tried messing with or resetting the distance-compansation tripmeter function yet??

mx284 wrote:

Have you tried messing with or resetting the distance-compansation tripmeter function yet??

Yes, thanks for the suggestion. I had tried that. :)

I gave up today and took it in to the dealer. It doesn't fit my "I WILL be Mr. Self-Maintenance-Man" edict, but it's only 2 months old and... it's electrical

Well then maybe it's a loose connection to the speed sensor. Or your speed sensor just took a dump and it's putting out the wrong voltage pulses to the speedo. I'm sure it will be covered under warranty if that's the case. Let us know what they find.

Well, the dealer checked out all the components and said it's the speedo head unit. Replacing the whole thing. Good part, under warranty; bad part won't have my bike back until next week.

Weird. Let us know when you are all fixed up so we know that was the issue. Any idea if the dead battery and/or push starting had anything to do with it? Or charging? (How many amps is your charger?) Something the rest of us should watch out for?

Bike is not fixed, but I'm riding it again. The dealer called and said he couldn't get the part. He had called the warehouse for Yamaha when the part was a no-show and they said they didn't have one. So, he called the other two warehouses in the states for Yamaha--no go. So, he called the big parts kahuna for Yamaha North America Corporate and there are NO speedo modules in the parts system ANYWHERE. I told them button it up and I'll drive it. Call me when they order some parts for the states.

Man that's a weird one
It's actually Not a good idea to run or try to run a modern electronic system with a dead battery, the stuff run's on microvolt's and the parts can frap with minor electrical spikes like connecting a high amp charger with the key on or jump starting the unit and disconecting the hot battery (like unplugging a home computer while it's booted up BZZZZZZZZT!!)
You will never be able to bump start this bike if you cannot get the fuel pump to pressurize the rail
Safe to say, if the battery is dead dont mess with it til it is charged at least enough to run the fuel pump

Well, she's all fixed now. New unit installed.

Actually you mention what I have come to believe was the 'failure moment'. The key WAS on when I plugged in the charger (just an old low-amp charger). I believe there was enough of a spike through the system that it wonked the electronics in the speedo.

*Warning to all*

Well, I don't know jack. The new speedo has gone wonky on me. Gotta take it back into the shop so they can "diagnose it". It's clocking 3X the speed and miles again.

No charger spike this time. Just hadda bump start it at work; took me a couple tries and she started up fine. But I'm now doing 189 MPH on the way into work (which btw is the max speed she shows).

Well you have the fastest WR on the planet, get some video of that before you fix it
Seems pretty weird to have the same failure twice, your dealer should put that speedo on a known good unit and make sure it's faulty before they just slap another on there
Maybe you just have a ground loop or something from a bad acc install or a connector issue

Sounds like the speed sensor is at fault here, and not the display. If the display was bad it may not show anything. If the sensor is bad, if will send bad info! You could try and simply disconnect it and lube the terminals with dilectric grease or silicone spray and reconnect it and see if that helps...

SpaGuru wrote:

Sounds like the speed sensor is at fault here, and not the display. If the display was bad it may not show anything. If the sensor is bad, if will send bad info! You could try and simply disconnect it and lube the terminals with dilectric grease or silicone spray and reconnect it and see if that helps...

Seems Yamaha agrees with you. They had the dealer order a sensor--backordered. They buttoned it back up for me without the part, and I'll go pick it up tomorrow and may try your suggestion Spa.

It's surprising that these things are as reliable as they are
The "Hall effect" sender looks at a gear and measures the time it takes to go from one tooth to another
Its possible the sender could have a little chip of metal on the face or something freaking out the message it sends out

Unfortunately you cant really test it without an occilliscope, cant even spell that!!

Looks like it's easy enough to pop out the speed sensor and see if it's clean or not. Did they try that?

malibu_dan wrote:

SpaGuru wrote:

Sounds like the speed sensor is at fault here, and not the display. If the display was bad it may not show anything. If the sensor is bad, if will send bad info! You could try and simply disconnect it and lube the terminals with dilectric grease or silicone spray and reconnect it and see if that helps...

Seems Yamaha agrees with you. They had the dealer order a sensor--backordered. They buttoned it back up for me without the part, and I'll go pick it up tomorrow and may try your suggestion Spa.

malibu_dan,

Did you ever get this problem permanently fixed? If yes, what did it take to correct it?

Thanks,

Artoo

Sorry Artoo, missed this post.

In the end, after catywonking the second speedo unit, Yamaha made my dealer go through and replace almost every component, including what I believe was the culprit--the wiring harness. Total bill was over $1200 (under warranty, thanks) for everything. After replacing everything conceivably connected to the speed sensing, it was still reading the wrong speed. SO... they agreed to replace the head unit again--fixing it. What is different this time, is I've not been able to break it again.

I believe there was some short or something in the system that caused a back-feed to the head unit when I bump started it (the offending act each time). I believe when they replaced the wiring harness it corrected the problem, as I have since bump started it with no complications.