motorbike problem?

Question

i have a old 1990 kawasaki gpz500s,that i use for work.For some reason today it will not start.
The only time it will start is when i get a jump start.Ive had the battery on charge,so the battery is not dead,but it just wont start from its own power??? .Could it be a weak spark at the plugs?.
because as soon as i get a jump from another battery its ok??.battery charging ok on a run,but as soon as you turn it off,wont fire up,dont want to keep trying as will drain the battery..any ideas??

Answer 1

Ask your local motor factors / auto supply store to check the battery. They should have a device which checks the charge. Using a voltmeter will give the volts but the real reading is the amount of amps.

Their device will check the volts and the charge at the same time.

If your battery is reading 12V, it is probably fried as it should nominally read up to 13.8V.

If your battery has a label on it with a date and it's more than three years old, get a new battery.

If it's a battery that can have its cells 'topped up', it's probably become sulfated (http://en.wikipedia.org/wiki/Sulfation)

You can attempt to revitalise a sulfated battery with special tablets that can be dropped into the battery along with distilled water to cover the plates again but for the sake of a guarantee and better service for the next two to three years, take the plunge and buy a battery.

If you still experience difficulty with the new battery, the alternator magneto / dynamo may need attention.

I've never owned a bike but I once had a car that had a faulty alternator. Also fixed for £20 by a guy who specialised in them. Found him in Yellow Pages...

Answer 2

Have you checked voltage across battery when it is running? should read up to 13.4v max. If over or below 12v, this could be regulator/rectifier problem. My ER5 was the same (It's a gpz without the raa really.) I put fresh plugs in but it still did the same.

The reg/rectifier might be ballsed up and not letting enough volts get through to start the bike, if you get what I mean.

My reg/rectifier was overcharging the battery (and over heated it too.)and killed a perfectly good brand new battery, so watch your battery is keeping charge too.

Answer 3

this sounds like it needs a new battery as it seems to lose its charge under any type of drain, its probably got 1 or 2 dead cells. you can get the battery check under stain in most workshops or just buy a new one for approx £20. they normally only last about 3 years if used every day but i would recommend to change once a year, you cant put a price on reliability.

Answer 4

Sounds like your battery is only just holding power, if all the terminals are clean and there is plenty of acid in your battery then you probably need a new battery or even a new dynamo/alternator ?.

Answer 5

it sounds like your battery has a dead cell, it happens on old battery's the plates make contact internally this creates a short circuit take the battery off the bike take it to your local battery centre thy will check it for you its only a few minutes job so the will probably do it free

Answer 6

A jump start is effectively using another battery. Your battery is shot I'm afraid.

Answer 7

There is either or a dead cell, or one of the terminals (check all ends, not just at the battery) is really dirty and it takes that much more amperage to get things going.

Answer 8

You don't mention wether the starter motor turns over or not,assuming that it does it could be a weak spark at the plug,faulty HT wiring or defective coil.It could also be low compression due to a loose plug or blown head gasket.

Answer 9

Sounds like a dead cell in the battery. See if you can try a new one. If that cure it, you'll have to get one.

Answer 10

There is a dead cell in the battery get a new one.