sorry about the air screw , thats is weird as we do set them 1-1/4 out.
on the plug , we carry them..
as well as
sparkplugs.com
BR8ECMIX
its the iridium version of stock plug in many KTM and a few KX models
on riding the bikes, if its giving you arm pump..
best techniques to help are
1, shift up..it has a lot of bottom end, use it..and let it pull dow nlow, it may sound like you arnt going fast..or "on the pipe"
but you will be goin gplenty quick.
2, try to grip the bike with your legs.. not the arms