No spark until I let off of the starter.

JaxShane650

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So I'm having an odd problem with my 1980 XS650 that has seemed to develop within the past couple of weeks. Whenever I go to start the thing with the electric starter, it will crank over perfectly fine but won't fire up until I let off the starter button (when the engine is attempting to slow down). Now when I use the kickstart it fires up no problem. Tested the battery and it seems to be fine, it's only about a year old and I keep it on the trickel charger over the winter. Of you have any ideas I would greatly appreciate the input especially if you have delt with this exact issue.
 
From the sound of what you describe the battery is weak. The starter draws in excess of 75 amps. This much draw can pull the battey voltage to below 10 volts. The TCI don't like that much.
What trickle charger do you use?
Some of the very cheap trickle chargers are ok for car batteries but not so much a bike battery. The cheap ones are not very well regulated. They rely on the resistance of the battery to control voltage. This resistance decreases as the battery charges and this lets the voltage go too high. Or is it just the opposite. Any way the more expensive ones are well regulated. They use a computer chip the read the state of charge and vary the charge rate to match the battery charge, When low battery charge they charge at a higher amperage, When the battery reaches full charge the charges lowers the amperage. This helps keep the battery from going over about 13.8 volts. Above this voltage the battery starts to out gas. This means the water evaporates. In a regular battery the cell dry out and seldom come back even when filled back up.
In sealed batteries they reclaim moist of the water.
Still the high voltage can hurt sealed batteries as well.
If you want to use the cheap trickle charger don't leave it on for extended periods. Over night maybe then check charge. Once charged you can leave it unhooked for a month or so, Check charge, hook back up as needed.
I might suggest you take the battery and get it load tested.
Leo
 
So I'm having an odd problem with my 1980 XS650 that has seemed to develop within the past couple of weeks. Whenever I go to start the thing with the electric starter, it will crank over perfectly fine but won't fire up until I let off the starter button (when the engine is attempting to slow down). Now when I use the kickstart it fires up no problem. Tested the battery and it seems to be fine, it's only about a year old and I keep it on the trickel charger over the winter. Of you have any ideas I would greatly appreciate the input especially if you have delt with this exact issue.

Hi Jax,
Yeah, same deal with my Heritage Special, new battery fixed it. Car battery with the sidecar fixed it REAL good.
I'm with Leo, your battery is hooped, it's only got enough Volts to work the ignition when it ain't working the starter.
Quick'n'dirty check, see how well the bike starts when you boost it's battery with a car battery.
 
Last edited:
Hi Jax,
Yeah, same deal with my Heritage Special, new battery fixed it. Car battery with the sidecar fixed it REAL good.
I'm with Leo, your battery is hooped, it's only got enough Volts to work the ignition when it ain't working the starter.
Quick'n'dirty check, see how well the bike starts when you boost it's battery with a car battery.
I'll try that this weekend. Also it seems to sometime start just fine after I changed the starter fuse but still sometimes has no spark till I let off. Thanks for the suggestions guys, I'll update once I figure anything else out.
 
If you do jump start from a car, DON"T have the car engine running. Most cars have 75 amp + alternators. Regulators on field excited alternators turn the power on/off to the rotor to control output.
When the car is running and you try the E-start on the bike the load of the bike starter draws the car battery voltage down, the cars regulator sees the voltage drop and turns on the power to the rotor, this in turn maximizes the cars alternator output. You get a surge of 75+ amps into a system designed around 16 amps. Something is gonna give.
On the 83 I just got on the road this year a PO did just that. It toasted the ignition system, TCI box as well as the pick ups on the stator. Luckily that's all it hurt. Everything else is fine.
Leo
 
Other possibles for this issue
Bad ground strap (corrosion)
rotted fuse holders in the fuse box (common)
Dirty poor contacts in the ignition and kill switch. (they face up, rain enters)
Other poor, corroded connections. (bike is forty years old)
Yes many of us have dealt with this exact issue, It's not just the XS650 that gets this symptom just started a restored XS850 acted the exact same way.
 
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