If you manage it you’ll have to let me know your technique. Thanks to where the battery is hidden I can never get a good enough contact with my jumper pack!

I would have said 12.85 is OK but it's worth putting the voltmeter on the battery then trying to start to see what the voltage is in that state. If it doesn't drop appreciably then I'd be looking at the relay and the side stand switch as well as checking all connectiones between the relay and the starter motor. If it does drop then I would be suspecting the starter motor itself. Or as said the battery.

Most thorough way is to trace the wiring through from the relay to the starter motor and check voltage at each point.

My partner used to work in a Harley dealership as a service manager. She said that they'd often get batteries reading an OK voltage, but when you tried to put a load on them they'd fall flat on their face. I guess there are multiple ways a battery can fail! They used to use a dedicated load testing machine that cycled through a battery to find out if it was really knackered or not. Honestly, the best way to test is to swap in a new battery and see if that fixes things. Not cheap, but effective.

According to this: https://www.matchlessclueless.com/elect ... -voltages/ (or other sources) i'm mis-remembering my voltages - 12.85 does sound pretty good for a standard lead-acid. But then I think my battery was reading OK until I tried to hit the starter at which point it only had enough energy to trip the relay, not to turn the motor over...

Nick

So now...

Brand new battery in place.
No start
Tried the emergency mode procedure with the weird raising & lowering of seat and inputting ID code.
Interestingly despite multiple tries the smart key indicater light did not give me the 10 seconds of flashing to acknowledge correct code -it just stayed lit.
Double checked code - definitely coorrect.
No start.

Software problem?

The hunt continues...

Oh bugger! However, I'm surprised that if its the immobiliser system, it lets you get so far along the process. I'd have thought it would have stopped you at the 'switch on' or even 'unlock' phase, but its letting you go all the way to start (everything else seems to be working), except for the starting itself!
The emergency procedure sounds far too complex to be a realistic proposition!
It could be the bike systems themselves, or it could be the bits relating to the app...

Does the starter solenoid click?... Could be started jammed/ stuck

starter not started, damn autocorrect

Thanks TC - I'll consider that.

Really appreciate support from all.

Oh man...this is starting to sound exactly like what happened to me just 24 hours after I brought my used 2017 model home: https://boymeetsbike.com/2019/09/22/i-b ... ax-530-dx/

Same symptoms - computer fired up, dash lit, all the buttons worked, no start. I had to have a Yamaha dealer come and take it away and eventually hunt down a damaged wire behind the fairing that was effectively a "Go!" signal for the immobiliser. They couldn't explain why it had suddenly failed, suggesting that it had looked cut. I figure it was damaged at the factory or maybe pinched somewhere and I was just unlucky to be holding the key when it gave way. Six hours of labour wasn't cheap, but they found it and fixed it, and 10,000 miles later I've had no further issues.

I really hope I'm wrong; I really wanted it to be the battery...but I do think you might be in dealer territory now. If it's a 2019 it might not be so far out of warranty that Yamaha might cut you a break?

Nick

Sorry not to have update earlier - been away.

OBD2 reading - no faults found.

Today I trailered it to the nearest (solely) Yamaha dealer.
They may not be able to look at it for a couple of weeks but at least I feel I'm heading for a cure (and a bill...)

Never been unable to get a bike going in the past. ? damned electronices. We shall see...