Flames, pops and bangs after flat battery
Discussion
Probably nothing to worry about but I took my trickle charger off my Hypermotard 939 about 4 months ago to charge something else and forgot to replace it. The battery was down to 4.4v this weekend, charger couldn't recover it so I put a new one on and started it up.
I let it get up to temperature showing about 90 degrees on the dash then gave the throttle a little tickle. It shot a bloody great flame out the exhaust!!!!!! Every little rev would result in a pop and bang, usually blue flames and an occasional yellow one. The throttle response also felt a little woolly, not nearly as crisp as usual.
It's never really done this before, my immediate thinking was the ECU had reverted to some sort of "safe" map having not had power for a while and was running really rich. Is this a thing or am I making things up in my head?
I plan on taking it out for a decent run and Italian tune up as soon as it warms up a little, supercorsa SP aren't much fun in this cold weather.
I let it get up to temperature showing about 90 degrees on the dash then gave the throttle a little tickle. It shot a bloody great flame out the exhaust!!!!!! Every little rev would result in a pop and bang, usually blue flames and an occasional yellow one. The throttle response also felt a little woolly, not nearly as crisp as usual.
It's never really done this before, my immediate thinking was the ECU had reverted to some sort of "safe" map having not had power for a while and was running really rich. Is this a thing or am I making things up in my head?
I plan on taking it out for a decent run and Italian tune up as soon as it warms up a little, supercorsa SP aren't much fun in this cold weather.
Most likely a temporary issue - I've had the same with my Monster when it's had a flat battery.
Start it again a few hours later and it's fine.
Could be a stuck open injector or poorly coil if it doesn't improve, be worth getting diagnostics done ASAP if it persists; if you've still got a cat then they can be damaged by very rich running
Start it again a few hours later and it's fine.
Could be a stuck open injector or poorly coil if it doesn't improve, be worth getting diagnostics done ASAP if it persists; if you've still got a cat then they can be damaged by very rich running
Krikkit said:
Most likely a temporary issue - I've had the same with my Monster when it's had a flat battery.
Start it again a few hours later and it's fine.
Could be a stuck open injector or poorly coil if it doesn't improve, be worth getting diagnostics done ASAP if it persists; if you've still got a cat then they can be damaged by very rich running
No cat, it was contained inside the standard can, got a nice shiny Akra on there.Start it again a few hours later and it's fine.
Could be a stuck open injector or poorly coil if it doesn't improve, be worth getting diagnostics done ASAP if it persists; if you've still got a cat then they can be damaged by very rich running
I'll start it again tomorrow and see if it's cleared up at all
spuds1 said:
Do bike ECUs alter fuelling based on sensor readings (thinking O2 / Lambda) over time? Could just be that the flat battery nuked the stored settings and it needs a run to sort itself out again.
That's my train of thought too, the fact its 0 degrees in the garage is probably causing it to run even richerspuds1 said:
Do bike ECUs alter fuelling based on sensor readings (thinking O2 / Lambda) over time? Could just be that the flat battery nuked the stored settings and it needs a run to sort itself out again.
Yes they do, but in theory it shouldn't be so rich under any circumstances, that said it's a Ducati so maybe! 
May not apply at all to your bike, but with the triumph ECUs on the bikes I've had it either needs several cycles of cold > hot, or several starts not quite sure to settle itself down after being remapped, which I'm wondering if it does in the case of a flat battery. Maybe something like that going on.
TimmyMallett said:
Would it be that it pumped fuel in, it didn't fire aa the battery was low and not enough to spark properly, that fuel ended up in the exhaust and ends up being ignited there?
I wouldn't imagine so, the battery was so low that the dash didn't even come on and fuel pump didn't prime.marksx said:
May not apply at all to your bike, but with the triumph ECUs on the bikes I've had it either needs several cycles of cold > hot, or several starts not quite sure to settle itself down after being remapped, which I'm wondering if it does in the case of a flat battery. Maybe something like that going on.
I think this is probably the most likely reason for it. Been hectic at work today so not had a chance to run it up again but I'll hopefully get a chance tomorrow Gassing Station | Biker Banter | Top of Page | What's New | My Stuff