125-200cc Newb seeks help with WR125 2002

Hi all
I have this old thing to mess with until I have enough saved for a newer bike.
Anyway it has had starting and running problems that have been a bitch to identify. I think i have narrowed it down to the ignition coil but cannot find any decent specs for it. I am getting around 700 ohms on the primary which seems very high and about 10k on the secondary which seems ok. The bike starts sometimes but cuts out as soon as any throttle is applied.
So if anyone can tell me what the readings should be or advise on where to get a new coil in the uk would be much appreciated.