amperage cant be the issue. Charging amps on a cane is around 480-500 and typical car is 80-150 -way higher. As one guy with the Jeep mentioned about the possibility of amps frying your system, thats impossible. CCA ratings for a bike are usually 160-280 but higher amps wont cause overload of a circut as the more CCA's are recommended. More likely causes are incorrect hook up of jumpers or wrong polarity is my guess....

 

I think Gill nailed it. I remember that in the old days many Brit autos were + ground(earth). Are they still? Our bikes are - ground. Hooking up the wrong way would deffinately fry the bike's electrics.

 

The car i jumped my bike from this morning was a honda prelude. It was suggested to me that maybe the spark plugs are bad on it. Does that sound likely to anyone?

 

Same here, no positive earth vehicle in the uk for many years. A friend had a Triumph TR4 many moons ago and I think that may have been + earth.

Now how would you jump start that if it was flat???