Bike won\'t go..... battery issue.....
 

I know i should be answering all of my questions here myself.... but i think i'm missing something.

Fired the bike up yesterday after giving the bike a charge and pootled round the huge car park for 10 mins to warm it up and run for a while. Didn't take the multimeter reading at the time as i wanted to start it again from cold.

So got in today and fired it.... Not even close.... everything turning over, but simply far to slowly and without enough power to get close to starting. MM is reading 12.61v

Now i was under the impression that anything over 12.5v would be fine for cranking it over ?

I'll charge it up in a bit and get it running again about lunchtime just to check with a MM that it's charging when running.

Battery is 2 years old and has only been ridden once, but i get the impression it was well looked after in garage with Optimate.

Hello weeksy2

I had a simular problem, would put the bike on the optimate over night,
all was well the next day, went out for a spin then the bike would die a death. I could not understand why as it was charging ok. After checking the wires from the regulator (replacing them with heavier grade wire (maplins do a good selection of wire) I then decided to purchase a new battery, (over 2yrs old) and hey presto all well. One thing I did notice you must be careful how you connect your Optimate up if you get it the wrong way round ie connect to bike while on at mains this will distroy your battery.

hope you get it sorted

PS I am trying to contact Marlon is this number correct? 017083797721

regards

TopiToo


[Edited on 15-07-1968 by TopiToo]

Hello

Damm just realized to many "7's"

regards

TopiToo

hmmmmm maybe 12.61 simply isn't enough. Can't really get a new battery right now.

Did try the Mrs' 748 battery but that was a pathetic little excuse for a battery :)

Don't know on Marlons number fella sorry.

Either the battery isn't supplying enough current or too much current is being lost in the circuit path. Steve's idea of replacing the wiring with a thicker guage is an excellent one - even if the battery is a bit weak it will give it an easier life with the thicker guage wires.

steve thats a digit to long


Have you tried the old Tecmoto number
01708 343916.

Weeksy I suspect the battery needs replacing, 13.2 Volts is a fully charged battery although 12.6 isn't bad. The smaller battery on the 748S is also the one they use on later 996s and the 998 so should be up to the job of starting your 916

[Edited on 30-12-2005 by skidlids]

Two quick thoughts

1 - temperature makes a big difference to a battery thats not quite at its best - which is why leaving it on charge could make a difference cos the internal temperature will rise when charging.

2 - if you measured the volts at the battery terminals, thats not necessarily what is getting to the bike ! Measure the voltage from the frame to the starter solenoid input terminal to get a better picture.

(I've banged on about the battery earth terminal bracket before - the stupid little bolt on the right-angle bracket is a spline fit which can loosen and cause a duff connection. I centre-punched the back of mine and then soldered it up.)
Its this kind of duff connection that makes 'smart' chargers cook batteries too !

got a pic of where that part is exactly mate.... i know roughly, but which end etc, i dunno.

No pics here at work :D
I'll try and describe it ...
looking at the battery from the right side of the bike, on the left side of the battery is the earth terminal, with a right-angle bracket bolted to it with the bolt pointing up.
The earth wire which goes to the frame is connected to the bracket with a bolt pointing to the back of the bike. Except its not a bolt cos theres not enough space, so they splined a stud onto the bracket, and if you tighten it up the splines slide and you get a worse connection.
There is enough resistance on this connection alone when its bad to stop the starter working properly.
A new one isnt a fix, cos its just the same, and as soon as you tighten it its will get worse.
The solution is in 2 parts :
take it off, knock the spline back through a mm or so, centre punch the back of the stud, knock it back flush so it wont pull out again when you tighten the nut.
Then solder it up at the back (where you centre punched) to get a good electrical connection.

Of course, it wont fix a battery that is past its best, but it all helps :D

well i never got a chance to do that bit and after tomorrow the bike is on a trailer off to go see Nelly for fettling.

Will have a discussion with him about it.

thanks for the adivce chaps.