My 4 year old street triple wouldn’t start after filling up this evening. Seemed to be trying, everything pointed towards a flat battery. After a few goes there didn’t seem to be enough oomph to even attempt to turn the engine over.

Anyway, it was close to home so I walked home and came back 45 minutes later with the car and some jump leads. Started the car and drove the 1km home.
The bike now seems to start with no problems whatsoever. Turns over and starts as well as ever. This makes me think it’s not just a flat battery. Maybe an electrical gremlin?

Any ideas?

Earth strap?

Rectifier?

Petrol not turned off and flooding a cylinder? (check the oil level, it’ll be high and runny if it’s this).

No fuel tap.
Earthing sounds feasible.
If it was the rectifier (and therefore flattened the battery during running) , wouldn’t it stop running once the jump leads are removed?

No idea, I just remember it begin one of the things to check.

There might not be a tap, but there might still be a valve, the one time I heard of it happening was when the automatic vacuum activated valve failed. Although having typed that and seen your bikes 4 year old it seems unlikely to have gravity fed carbs!

Not been left out in rain, bit of water in tank?

Battery. I rarely get more than 3 years from a big bike.

Battery is a good place to start, bike batteries and charging circuits are often pretty marginal because it’s a place they can save quite a lot of weight. Though, failing during a ride like that would point more at charging than battery. With japanese bikes it’s basically always the regulator/rectifier.

Have you got a charger and a multimeter?

If you do end up replacing the battery, it’s worth looking for upgrades- I put a slightly larger, much improved battery in mine- more capacity and a lot more cold cranking amps, basically means it turns the bike over harder which made a huge difference for cold starts.

No charger, but I do have a multimeter, so I should be able to check the battery in its current state.
Sounds like it might be worth a punt on a new one anyway.
So, what manufacturers should I be looking at for better than oem batteries?

See if it fails to start tomorrow morning when it’s cold – it which case probably battery.

It’s worth looking at LiPo batteries these days.
I’ve got a Shorai on my 1098 and it starts instantly.

sam_underhill – Member

No charger, but I do have a multimeter, so I should be able to check the battery in its current state.

OK, you might know all this already so forgive me if you do.

First, check the voltage with the ignition off, you want to see about 12V
Then, check the voltage with the ignition on and the headlights on, see if it drops much. I don’t know how hard your bike draws, but I’d expect to see it no lower than 11V. If it drops lower then generally the battery is either not charged, or buggered.
Then, start it and hopefully see over 13V (apparently, for most trumpets- this varies a bit, my suzuk/honda mashup charging circuit showed 14)

Cheers folks.

I think you’d expect to see a bit more with the ignition off. 12.7v would be a really healthy battery.

Good point that, I’m making some allowances for it having been flat yesterday but yep, depending on exact battery you want to be seeing high 12s ideally.

Is it used regularly or often laid up, if the latter then you may want to invest in a trickle charger.

FWIW I’ve never put a new battery on a bike, but then I’ve always used them daily – whereas I know folk who only use them occasionally and/or summer and they’re often at yearly replacements.

It’s used regularly, although for the last few months it has had periods of a couple of weeks at a time. This is probably normal in the winter.