Having trouble with a weak spark on my Honda XL250R. We think the source coil is at fault but on test it gives 76 Ohms resistance. The correct resistance is unclear as the manual we have says reading should be in the range 200 to 500 Ohms. However later it says that for post 1981 the reading the range will be 50 to 200. Not clear if this is a misprint. If it is not the source coil we will have to look elsewhere for the reason for the weak spark. Any help gratefully received