Carb Jet & Sparkplug

[vitamin*g]

My Buggy came with a K&N air filter and an FMF Exhaust. I opened the Carb yesterday and noticed the main jet had a 145 stamped on it. I just added a performance CDI, Coil & Iridium Spark plug. My 1st ?, Is this Jet to big? Also, My old Sparkplug size is C7HSA but the Kinroad website states the the unit should have a A7RTC sparkplug. Is there any difference?

[BuggyMaster]

What kind of buggy is it? For the jetting, I'd like to see a picture of the spark plug after use. On our Helix, with fmf exhaust and uni filter and cam, I needed a 150 jet to get the proper AFR so you may not be that far off.