starting trouble

[floridajoe]

this i find strange. my 79 xs put new pick ups on started great run better then ever. then it just died battery great charge power to all contactes. bike will turn over great no drag at all. if i put a battery charger on it but it to boost start and guns runs great. turn if off will not start. i dont know what it could be .. ps charging system also working thank you all the past help

[trbig]

I'm not quite understanding. If the battery is great and is charged great, why would you have to jump it with the charger?? Almost sounds to me like it has enough to crank it but not nough volts for it to run?? But, since recently changing the pickups, that's the first thing I would suspect.... loose wire maybe?
Have you checked the compression lately? Sometimes if it gets really low, you may need a few more amps on cranking to make it spin fast enough to start?? OK.. I'll admit that I am sitting here at work, bored, and grasping at straws here... lol. Good Luck.

Tod

[DiverRay]

Put a VOM on the battery and check voltage when you crank. If it's below ~10.5volts, no fire. You could have a bad battery, with one or two cells partially shorted. If that is the case, battery will show 12+ volts at no load, but below 10V as soon as you put a load on it.
Ray

[GNEPIG]

.. it sounds to me like the balist resister has gone bad.
take the spark plugs out and lay them on the head, then turn the motor over and check for spark. you might find you only get spark the instant you let off of the starter button.

[John]

The ballast resistor is bypassed when the engine is cranking. It is in the run circuit. The coils need a full 12v when cranking, but only about 9v when running. They may be 'competing for voltage ' with the starter, and they are going to loose. If it runs with the booster hooked up then I would suggest testing the battery with a load tester, or just replacing it.

[floridajoe]

i have put in a new battery a good gel battery test the old and new load test is good. i work in a auto parts store i have lots of batterys. how would i test volts to the coil on crank up

[John]

Just probe the wires feeding voltage to the coils. Remove the tank and locate the coils. You will find one coil has an orange wire and a white, with red stripe. The other will have a grey wire, and white with red stripe. Unplug the coils and crank it over.Test the orange or grey wires when it's cranking. They should have battery voltage in the crank mode. The ballast resistor will cut the voltage down to about 9v when it is running.

[TopCatGr58]

Hey Joe,

When you were boosting the battery, WHERE did you connect the cables, to the battery posts, or further down on the solenoid?

Have you removed and thoroughly cleaned ALL of the wire connections between the battery, the solenoid, starter, etc.???

I remember once trying to boost a car, and even with jumper cables, it wouldn't start. THEN pulled the cables off the posts, found tons of corrosion, cleaned the terminals and clamps, and then it started WITHOUT needing boosting!?
T.C.