XJ 900's?

Does anybody on here have any knowledge of the 1987 Australian released XJ 900?
I'm having problems getting spark on 1 and 4... the spark on 2 and 3 is there but very weak.

 

In any no-spark situation the first step is to make sure that the battery is capable of holding a full charge, and passes a voltage-drop load test.
Hook a volt meter to the battery terminals and see if it drops below 10 volts when you hit the starter button.

IF not, then start looking at the coil primary leads to make sure they are clean and connected well. If the spark plug caps are removable (they will unscrew from the wire) check for corrosion at the plug wires (cut the wires back a bit if you see any corrosion, then reinstall the plugs), and swap the plugs around to see if the problem follows the plugs (in which case the plugs are faulty).

After that, then you will need to check the resistances of the primary and secondary sides of each coil.

 

Thanks for your input k-moe.
The battery is a brand new Motobat MBTX14AU but, yes, the voltage drops from 12+ to 8 on the ignition cicuit when I hit the starter button.
I'll follow your suggestions and see what I come up with.
Cheers.
Rob.

 

Even new batteries can be faulty. I'd take it in and have it load tested by the seller.
The other possibility is that the starter motor is in need af a rebuild, and is drawing far too much current.