No sparks = no go

[James England]

If you used a car or truck battery (400 to 600 CCA or better?) with regular jumper cables (not speaker wire) there would be a serious smoke leak most likely followed by a shower of melted solder, copper and steel from that poor little motorcycle starter when it drew enough current to pull and hold the voltage below the 10V necessary for the TCI.

Are you sure about this? Doesn't an electrical device pull only the amount of current it needs? I just started up a project bike by using thick jump leads off my car battery with no damage to anything at all. It started the engine, I then disconnected the jump leads and that was that.....

[Rasputin]

Have you tried removing the ballast resistor and connecting the two leads together to see if you have spark while cranking? A bad ballast resistor can cause the spark when you stop cranking but produce no spark while cranking. Also it does not take a whole lot of starting attempts to run one of these batteries down even if it is new, which will slow the starter down. JAT

[natemoen]

Also while checking the starting system, have you checked for any voltage drop from the battery to the starter?

Is there anyone near you that could give you some hands on help?

[DAVINCI]

James England: Correct, a device will only pull the amperage it needs.

Rasputin: You got that backwards, the ballast is bypassed during cranking.

3phase has good advice:

Check for:

Bad pickup coil connection at the TCI - Don't forget the harness connector behind the fuse panel.

Bad or broken pickup coils/wires

Bad or mis-installed tipover switch

Bad TCI.

[3Phase]

Are you sure about this?

Yes, James, I'm sure. Loho has connected a car/truck battery to his bike several times and has not mentioned any pyrotechnics so a shorted starter motor is possible but unlikely.

If there is no problem then the XS11 starter motor will work with any 12V battery that can meet or exceed the rated amperage for the motor but there seems to be a problem with the starter motor on Loho's bike.

When the starter motor is shorted then the amount of smoke and light in the show will be roughly proportional to the type of short and the size of the battery used to produce it. A motorcycle battery may not supply enough current for a proper show but a larger battery will do just fine. It is a little harsh to attempt to locate shorts by pouring great gobs of amperage into them until they fail but it does work.

Always wear safety glasses and have a good fire extinguisher in the work area.

[cywelchjr]

Are you sure about this? Doesn't an electrical device pull only the amount of current it needs? I just started up a project bike by using thick jump leads off my car battery with no damage to anything at all. It started the engine, I then disconnected the jump leads and that was that.....

I had to read it 3 times and I think what he was saying is that if something is wrong enough with the starter to pull a car battery down under 10v while cranking it would be pulling enough juice to melt the starter down.

[motoman]

Sorry for the frustration there Larry. Least having a known good battery eliminates that as being the issue. Sounds like you have a project 1100, so swap out the starter as that is easy enough to do and see what happens. These issues make it difficult to sort out not being there. Persistance WILL overcome these scoots and there needyness. I presume it's the same scoot you had at the rally two summers ago?

[3Phase]

I had to read it 3 times and I think what he was saying is that if something is wrong enough with the starter to pull a car battery down under 10v while cranking it would be pulling enough juice to melt the starter down.

Exactly. I should quit reading technical forums after midnight and just go jogging or something if I'm not sleepy.

[Rasputin]

Rasputin: You got that backwards, the ballast is bypassed during cranking.

Ok I got it bas-ackwards. I am wondering though in my addled brain if it still may work. Would not removing the ballast resistor provide 12 volts to the coils no matter if the starter circiut was or not? Electrickery and me are not very good friends as the whole concept eludes me completely

[crazy steve]

Ok I got it bas-ackwards. I am wondering though in my addled brain if it still may work. Would not removing the ballast resistor provide 12 volts to the coils no matter if the starter circiut was or not? Electrickery and me are not very good friends as the whole concept eludes me completely

Yep, removing the resistor would do that. But the TCI unit can't take the increased load on a full time basis, so you'd let the smoke out.

Everyone knows that once the smoke is gone, you need a new part that's still loaded with factory smoke...

[Rasputin]

I mean for a short time to try. If it fires up doing this may narrow down the problem area.

[cywelchjr]

Well, it might be worth trying if it were firing and dying when you let off the starter that would be a good step, and might be some worth trying anyways, but it's bypassed anyways while the starter is running. I'm still wondering if the tipover switch has been unplugged as a test yet. If it's bad, it's the easiest way to test that, and it would account for the symptoms.

[petejw]

as been stated,

the ballast resistor only reduces voltage
to the coils while the engine is running,
when the engine is being started its using
12v battery power to the coils,

Yep, removing the resistor would do that. But the TCI unit can't take the increased load on a full time basis

hi crazysteve,
thats not right,

bypassing the resistor will only put extra load
on the stock coils and wont affect the TCI in
any manner.

[cywelchjr]

Neither the coils or the TCI are designed to handle the current level without the ballast resister, and as such either one may fail, its just a matter of which one overheats to it's "let the smoke out" point first. Simple electronics, the weak point will fail, I believe that evidence has generally shown this to be the TCI rather than the coils.

[petejw]

hi cy,
the ballast resistor affects the coils only,
theres no voltage going to the tci from the ballast resistor
have a look at a wiring diagram,
whether its connected or not wont affect the tci.