Cold starting problems with 400cc scoot

pappa_golf

the test using the lights is not the best to use , professional bike garages use a voltmeter that has 2 settings


setting 1: the voltage
setting 2: the voltage at cranking speed ,


the light test would only take a reading of the h/lamp , tail light and side light , perhaps 70w at max , that is less than 6amps , whereas cranking could take 100 amps


its the cranking voltage that is important , adding your jumper pack would allow a good cranking voltage

facade

Cash-Strapped.T32 wrote: »

The only device I have that can check the voltage is the battery charger (one of those Oximate types, that gives a voltage & ampage reading on a little LCD screen)...

Would that work in this test? And what's the purpose of the test?

If you don't plug the oximate into the mains, but press the selector switch so it has the little picture of a motorbike, it will read the battery voltage.

I wouldn't leave it on like that for a long time though

The test is to partially discharge the battery and see what happens to the voltage.


Is it a decent make of battery bought from a proper shop, or an eBay special, made in the Chinese Gulags?

It may be the battery at fault.

khcomp

I'd go with facade - if it starts fine from a jump or battery pack, the new(ish) battery may be faulty: I've had a decent new motorbike battery faulty on delivery within the last few months. Borrow a different one to try....

Cash-Strapped.T32

Woah - thread resurrection! :eek:

Just because I hate when someone asks for advice, gets it, and can't b bothered to come back & report if it helped or not...

I finally found & fixed the problem that had been plaguing this little scoot for months. I'll warn you, I had to use a very expensive, technical and hard to obtain tool in order to rectify the problem....

A tub of Vaseline.
I felt so daft when I finally figured it out.

This bike has it's battery located in the dashboard, where you'd expect a glove compartment to be.
After nearly 20 yrs on the road the glove compartment is no longer quite air/water tight (the door is only out of true by about 1 mill but the seals are shot) - This means any moisture in the air can get to it, and even on what seems like a nice day, residual moisture in the air must have been affecting it's cranking because as soon as I insulated the terminals with vaseline the problem disappeared like magic, instantly.

The terminals were regularly cleaned of corrosion, charging system was tested and shown to be working fine, the battery (and replacements) were fine, as was the wiring - everything seemed ok when being tested so it was really tricky to pin down using home tools/knowhow.

I know it sounds silly, but it was literally a night & day difference, the moment I insulated those terminals.
Clean the Vaseline off & it goes back to it's former behaviour, easily repeatable.

So, it just goes to show - after £80 spent on batteries in a year, and god know how many hours spent over that year messing around charging them, and jump-starting the bike, all it needed was a 50p tub of goo.
Anyway, hope this might help someone else at some point!