10 replies to this topic

[TeDeum]

Tried to start the bike on Sunday to go for a short bimble to warm up the oil so I could change it. Wouldn't start. Not even attempted to fire which is a first. Since I hadn't used it for a while I put the battery on charge and tried again the next day. Same result. Checked the spark and it was yellow and weak. Checked the primary coil resistance which was about double the spec on both coils. Couldn't get a reading for the secondary resistance on either coil which makes me think my meter may be dodgy on that range. Checked the battery no-load voltage and it was 12volts - a little under spec. Is it possible that the drain on the battery when turning over the engine would reduce the voltage so that there would not be enough current to create a decent spark? The battery is 10 years old so owes me nothing. Any other ideas please?

 

It's a 2001 Mk2a with 60k miles and has never let me down before.

[Bjørge]

12V on a charged battery is clearly too low. You could try jumper cables from a car to see if that makes a difference. Some peaople claim that it may harm your battery etc to use jumper cables from a car. I've done it many times  - no prob so far. If you don't start the car's engine it will not deliver a too high charging voltage.

[chrisr]

Yes

[TeDeum]

Thanks. I'll borrow booster pack from my mate this evening to check. Interesting that the OEM Yuasa or equivalent battery varies in price from €55 to €155 on the internet!

[Studley Ramrod]

According to Haynes book of stand up comedy greats, 12.5v is considered to be a flat battery sooooooo, 12v is reeeeeeally flat.

[TYREDNGRUMPEE]

10 battery years is practically immortal in human terms.

It just takes one of the cells to start creaking and the rest are crippled.

Don't leave it too long or go riding, knowing you have a fault; you may cause additional damage in the charging circuit.

[TeDeum]

Thanks for the advice. No danger of riding the thing since I can't start it. 

 

So this evening I'm more confused than ever. New battery coming tomorrow so I decided to take out the old one but first I wanted to try the battery booster to see if it would start the bike. The croc clips on this were too large to fit on the battery leads but I did manage to accidentally touch the +ve lead on the starter feed and the engine turned over briefly. After this I couldn't get the dashboard display to light up when I turned the key to 'on'. I checked all the fuses but found nothing blown. I removed the battery and stuck the meter on it which read 13 volts today! What possible damage could I have done by operating the starter motor without the key being in the 'on' position?

[Catteeclan]

Not the good old starter relay playing up again is it?

[Bjørge]

Thanks for the advice. No danger of riding the thing since I can't start it. 

 

So this evening I'm more confused than ever. New battery coming tomorrow so I decided to take out the old one but first I wanted to try the battery booster to see if it would start the bike. The croc clips on this were too large to fit on the battery leads but I did manage to accidentally touch the +ve lead on the starter feed and the engine turned over briefly. After this I couldn't get the dashboard display to light up when I turned the key to 'on'. I checked all the fuses but found nothing blown. I removed the battery and stuck the meter on it which read 13 volts today! What possible damage could I have done by operating the starter motor without the key being in the 'on' position?

 

None, I would say. Running the starter engine with no ignition should be harmless.

 

So, have you checked that all connections are good ? Look for a substantial voltage drop when you turn consumers 'on'. Start vwith measuring on the (lead) battery poles themself.

[TeDeum]

Thanks Bjørge. That is reassuring. I got the new battery yesterday but it was the wrong ones despite me using the correct number and dimensions so I was unable to do any further messing with the bike. Hopefully the correct one will arrive tomorrow and I can get stuck into it again.

[aytcat1]

Sounds like your starter relay has gone kaput,Bad connections inside.

There is a connection from the battery + to the relay the wire connects  by a exposed flat copper wire to the fuse, that corrodes and goes green in colour,and normally all the connections inside the relay break up caused by road crap and water,This powesr  the Block connection on top, feeds the rectifier,/gauges etc.

If you connect wire from Battery + and connect other end to starter motor on other side of relay and the motor spins i would think its the relay gone !Your gauges prob will not register either.

It will give you various voltage drops and readings,if your riding the bike will misfire sometimes etc like running on one cylinder then go back to running on two cylinders.