Breva Rev counter

Hi I’m a recent new member living in west Cornwall, can anyone help please?
After reconnecting my battery, the rev counter on my Breva 750 has not returned to zero, but has stopped at 4000 rpm! I have tried disconnecting and reconnecting several times but stays at 4000. Has anyone come across this before?
Thanks for any help you can offer!Â

Hi and welcome.

Got a Breva and Nevada, but not seen that one. Hope you find a fix.

This is new to me.
You may need someone with the computer system to check it out.
I cannot think of why it should happen except a faulty rev counter.
Does it read over 4000 when you ride it and are there any other symptoms?

Hi
When I turn on the ignition, the needle does it’s sweep starting from 4000 and returns to 4000, then when the engine is running the tachometer works ok, but just idles at 4000 and revs upwards from there. Very strange, trust me to have something that no one has come across.Â

Why was battery disconnected? What else were you doing with the bike? The problem may be because of something you did, like for example pull a connector apart or disturb something else that the tacho needs to work properly. But I’m just guessing TBH.

mm thats a weird one
did you by any chance flash the terminals when recconecting the battery ?
a surge could confuse it
try disconneting the sender and see if it returns
also worth doing is riding it for a while
I had a problem with weird lights coming on
eventually they cleared after a long run allowed it all to reset itself
otherwise disconnect the battery adnleave it off overnight
also check for water in the instruments
undo the battery earth first
then remove the connector block at the back of the clocks and warm it gently or let it sit in the sun for a while
before recconectign everything

I have replaced the battery and fitted an isolator to it, so quite likely to have flashed when reconnecting. Being a fair weather rider and the bike standing for periods, the old battery discharged after a week or so hence the isolator. There is no problem with the speedo, just the tacho.
It has been on a decent run, and has been disconnected a few times and reconnected to try to reset it but still the same. I will try disconnecting the sender, if I can find it!

Must not leave battery disconnected or use an isolator switch with these modern computerized vehicles, the electronics are designed to be powered all the time in ‘standby’ mode. And true even disconnecting and reconnecting may be fraught with possible problems.

If losing charge over time due to non use, then must put a charger on at periodic intervals, in lieu of the vehicle being driven.

Even then there is a risk of over Voltage, so the charger must be an ‘intelligent’ or Voltage regulated type. And not a trickle charger either, which is as bad as leaving it for too long in a discharged state, apparently! I.e. actually shortens battery life, the exact opposite of what is anticipated.

Just read this again ~ that doesn’t sound normal so you probably have a power drain, aka ‘parasitic drain’, that needs investigating. I.e. something is draining the battery charge, but shouldn’t be.

EDIT: unless simply because old battery was duff and wouldn’t hold a charge.

the computer and clock will slowly drain the battery
you either need to disconnect and remove the battery ( I do over winter)
or keep it plugged into an optimate charger
the problem with these computer thingys is that electrical surges or flashes on connector are akin an electronic earthquake
everything goes out of its normal order
where abouts in the country are you ?
it might be worth getting it plugged into the computer thingy to have the fault analyzed, and the software reset ?

I did have a drain on the battery, the oil pressure light glowed very faintly with the ignition off. I seem to have fixed this with a new switch, but thie old battery was pretty duff, which was why I replaced it.
I have just reconnected the battery without the isolator, but it’s still set at 4000.
Raphael - I am in west Cornwall, not sure if there are any of those computer thingys down here!

The oil pressure light issue is weird ~ should there not be any power at all in that circuit while ignition is off? See if battery drain is indeed cured, or whether is still being drained ~ the weird behaviour may not be just confined to tacho, the whole dash might be wacko…

I am sure its the same unit as used on Harley davidsons
the chap I use is based at Didcot, so a bit far for you
have you had water ingress problems ?
also just check the wiring harness around the headstock inc ase it has been trapped and severed a cable

Thinking back to when I had the oil pressure light problem, I removed the dashboard connector thinking that the light was picking up a feed from somewhere, possibly the clock, via a corroded connection or something. There was nothing obvious, but I sprayed with electrical cleaner and blew out with the air line.Â
So I guess your comments are probably right that there is a problem with the dash unit. Yesterday, I cleaned the connection again, it all looked ok, and had a bit of a look for damaged/trapped wires - nothing obvious. After switching the ignition on and off a few times the tacho needle stopped right around on the stop, then switching on again it has returned to zero!!! I have run the engine and it seems to function ok. I haven’t had chance to road test yet, Â but fingers crossed.
Thanks to everyone for your help and suggestions, I will let you know how it goes. Anyone know the best source for a replacement dash if I need one?Â

It could be as simple as the connector not makingproperly or a spot of corrosion
sometimes remaking them a few times clears the grunge
if the contact cleaner has entered the housing it may have caused the sticking, or some dirt moved by the air line

From reading elsewhere a complete replacement dash would be expensive.
To correct Mike H modern electronic components are actually quite tough and disconnecting the bty or putting in an isolator switch is fine.
I have left my li’breva for 2 weeks and had no problems starting afterwards. I have been told that problems start after 3 weeks.

My Nevada will discharge in just over a week wit a new battery, but that’s because the first owner thought a wretched alarm would be a good ideal.
My Breva however had been left over six weeks sorn during this summer as I have been running the V11 and the Nevada. Started on the button. No issues. Must try it again as I plan to bring it out next month and moth ball the other two.

Just to update on how things are going.
Managed to get out for a road test this weekend. On start up, the needle made it’s sweep from zero but stopped at about 7000 rpm, I started the engine and the idle level gradually fell to about 4000, so I went out on the road. The first 20 miles or so it seemed to have a mind of it’s own at some point it was showing 1000 at about 50 mph in 4th (Cornish lanes). After about 30 miles it seemed to settle and appeared to be running about right. I stopped after about 50 miles, left it for half an hour, and restarted, again after the sweep it stopped at  about 7000rpm but on starting it gradually fell back, took it out and after a few miles was behaving ok.
Very strange, Don’t think I will be rushing out to buy a dash, I will probably check through the wiring on the sensor circuit when I get a chance. Could it be a problem with the sensor?Â

More likely static or pressure build up in the meter.
If you can get to it separately (I have never tried) then a very small hole in the rear of the meter may be your solution.
On my V!! the rev counter needle used to wander all over the place until I did that and it cured it.

I’m not sure if that’s possible, I tried to strip the dash when I had problems with the oil pressure light to see if there were any obvious problems, but from what I remember it’s pretty much sealed. The problem has settled down a bit, not gone away but is better than it was, it seems to sweep and return to zero most of the time, but tickover registers zero. Will have another look at the dash when I get a chance.