She no go

[schnowz]

I agree with that. Sounds like it's something that's effecting all 4 
cylinders.
Have you checked the brown connector under the tank- it supplies power to 
the fuse box including the iggy IIRC
With 2 plugs out it's not as much work for the starter and won't pull the 
voltage down as far. So it may be enough voltage to get a weak spark. I 
wouldn't count out the battery or battery connection either..I know that 
normally if you have a bad battery it won't crank, but the GPZ iggy needs a 
healthy voltage and can crap out before the starter if you have a weak 
voltage and the ignition wires and plugs are'nt perfect condition. There is 
also a voltage drop at the iggy switch which doesn't help, but they normally 
go gradually and as Steve said if you switch on again they normally work  - 
at least for a while..
 For what it's worth i set out from the house on a trip to the Adirondacks a 
couple of years ago. I stopped 2 miles from the house and couldn't get it 
started again. I checked everything  - it would crank fine but no fire. I 
put on a new battery and Vroom I'm on my way..Though I know you say you 
jumped it so provided you have good connections then it may not be your 
problem..

  Pete Staniforth

 >>
>> Hi Simon,
>>
>> With # 1 and 4 plugs clean and dry it shouldn't be a flooding problem. 
>> Even
>> if # 2 and 3 had been flooded at least # 1 and 4 should fire up. ...?