TOPIC:

My bike fires up great in the morning, actually any time of day. Once I get to work and try to start it again, the engine doesn't turn over, as though the battery is dead. If I come back a few hours later, it starts again. I'm at a loss here.

A few points of reference:

• The battery is brand new. The previous battery was also new - I replaced it due to thinking it was the issue
• The reg/rec is doing its job, output is 14.5V while revving - tested right after starting and after a ride
• Sometimes though the battery is dead from the start, I'm not sure whether that is only after trying to engage the starter after the engine is hot

Could something be drawing so much power that it drains the battery? Would that not blow a fuse?
I made the fuse box myself, it was missing when I bought the bike. I'm sure it is good though as I followed the wiring diagram.

IOC750 wrote: the engine doesn't turn over, as though the battery is dead. If I come back a few hours later, it starts again..

Are you putting a battery charger on it in the time between?

Something could be drawing enough power to drain the battery ( for example high power headlight, other additional lighting added, heated grips ) faster than the charging system can keep up but I cannot imagine that it would be better later without putting a charger on the battery. A parasitic draw wouldn't blow a fuse.

Can you hear the solenoid clicking when you try to start it but it won't?

Take a multimeter with you on one of your morning rides and test the battery when it acts like this. That ought to tell you if the battery is charging properly or draining. If it still measure okay you can rule out the charging system and look at other areas.

Is it possible that the pistons or rings are binding when the engine is hot and the electric starter doesn’t have enough oomph to spin the engine? I would try the following to make sure that isn’t a problem – run the bike until it is totally warmed up then use a wrench on the crankshaft (under the ignition engine cover) to see if the engine will turn over without unusual effort. You can first try turning it over when cold to see how much resistance is normal.

Also, you could try checking the battery voltage when the engine is hot, but I suspect that’s not going to show low battery voltage with no load on it. Ed

diggerdanh wrote:

IOC750 wrote: the engine doesn't turn over, as though the battery is dead. If I come back a few hours later, it starts again..

Are you putting a battery charger on it in the time between?

Something could be drawing enough power to drain the battery ( for example high power headlight, other additional lighting added, heated grips ) faster than the charging system can keep up but I cannot imagine that it would be better later without putting a charger on the battery. A parasitic draw wouldn't blow a fuse.

Can you hear the solenoid clicking when you try to start it but it won't?

No I don't have a charger hooked up after, though after a few days the battery needs charge.
Edit: And yes, it isn't completely dead, I can hear it trying to engage. Headlight and turn signals still work after these encounters

650ed wrote: Is it possible that the pistons or rings are binding when the engine is hot and the electric starter doesn’t have enough oomph to spin the engine? I would try the following to make sure that isn’t a problem – run the bike until it is totally warmed up then use a wrench on the crankshaft (under the ignition engine cover) to see if the engine will turn over without unusual effort. You can first try turning it over when cold to see how much resistance is normal.

Also, you could try checking the battery voltage when the engine is hot, but I suspect that’s not going to show low battery voltage with no load on it. Ed

Thanks Ed, I'll definitely give that a shot tomorrow (it's nearly midnight here)

Friend of mine had a similar problem in a Honda .......so maybe that doesnt count
Hi bike would start fine first ride of the day and then parking for 30 - 60 minutes and coming back to the bike the engine wouldnt even turn over when he hit the starter button. He used to park on a hill and bump start. Turned out to be the starter motor.
If everything else checks out then it mighbe worthwhile removing the starter motor and cleaning up the innards.

Some how connect a meter to the battery and strap the meter to the bars and take a ride....looking at the #'s
If ok could be the starter getting hot and won't spin afterwards.
How many miles on the bike?

spdygon wrote: Some how connect a meter to the battery and strap the meter to the bars and take a ride....looking at the #'s
If ok could be the starter getting hot and won't spin afterwards.
How many miles on the bike?

The odo is somewhere at around 43 000km
This morning when I tried to start it, the engine turned over a few times and then the battery was tired. It's at home on a trickle charger now.

Wouldn't the starter motor only get hot if the starter clutch wasn't properly disengaging? I'm really hoping I won't have to dig that deep.
I've still yet to try Ed's test of manual engine turnover, I was hoping to do that at work today.

Hello
IMO the starter motor has a thermal problem (bearings / brushes to commutator).
when cold all tolerances are in spec but when hot some parts expand and cause more mechanical friction or electrical resistance.

Michael

I'm with Sirocco on this.

Scirocco wrote: Hello
IMO the starter motor has a thermal problem (bearings / brushes to commutator).
when cold all tolerances are in spec but when hot some parts expand and cause more mechanical friction or electrical resistance.

Michael

Thanks a lot, I'll take it out and have a look. I wouldn't be surprised if the brushes are worn with carbon all over the place, this machine was riding before I was born

Just thought I'd update you lot and leave some information for future reference.

I took the starter motor out and gave it a quick clean (I was at work and didn't want to be without transport at day's end) so at some stage I'll do this properly. While under the cover, I noticed that one of the three cables coming from the alternator had a dry joint. The lugs still have the factory heat shrinking on it, which has become brittle.

After properly inserting the lug, it seems my charging issues are gone.

The important info here, is that it seems that your reg/rec and battery will still give you a 14.5V reading at 4000rpm even though the reg/rec is only being fed 2 phase power instead of the full 3. If anyone has a different experience with this, please chime in, this is just what I have observed.

2 phase alternator input is definitely not enough to keep everything going.

Thanks all for your input.