99 Summit 500 weak spark need help

[Letitsnow800r]

My friend has a 99 Summit 500 that seems to have week spark. If he rides it on new plugs he can usually get a day or so then it wont start again. Put in new plugs and its off and running. Over the weekend I checked the spark with new plugs. It was very weak at best. Coil or further down the line. Any thoughts? Thanks

 

[snowfreak03]

could be the coil, otherwise i had to replace my ignition modual on my 98 summit? good luck