2 stroke spark plug advice

Wondering what guys are running for plugs in their 300 cc 2 smoker snow bikes, the iridium plugs or standard ones? I ask this because i learned two really important lessons yesterday about iridium spark plugs and being fully equipped for riding far away from main trails in backcountry deep snow... more of a total brain fart on my part in the end. I was "that guy" yesterday that didn't have a spare plug with him, and learned an interesting lesson that iridium plugs can just totally die at the less than ideal time without any warning. I have had plugs foul on my sleds before, and was able to use my little butane torch if needed to cook build up off of the plug and wire brush it and your good to go (and i always had spare plugs with me). I had no idea that iridium ones can just up and crap out while you are destroying all the powder you can get your hands on. It was like i had hit my kill switch and it was dead in the water... I bought this bike this past summer (2016 KTM 300 xc) and it has an NGK BR 7EIX iridium plug in it (bike is at home right now). I see in the manual they spec the bike with a BR7ES plug and am wondering if this works just as good as an iridium plug, or if there is a benefit to running one versus the other? going to buy three new plugs today...
Thank God for good friends that don't hold a grudge, because towing a dead bike out of the bush with two couples snow bikes is a crazy amount of work... Lessons learned the hard way definitely stick with you haha!
Last edited:
Nov 29, 2007
I run a standard BR7ES in both 300's and haven't had an issue in 2 years. Good to know about the iridium plugs, I didn't know they would die like that.


Well-known member
Lifetime Membership
Aug 12, 2012
Heber Ut
For sure standard... just the bigger tip I think it’s more reliable .

Sent from my iPhone using Tapatalk


Well-known member
Premium Member
Jan 26, 2019
Pemberton BC
I use standard. They're cheap so you don't mind changing often. Gap erodes over time, especially if you use leaded fuel. Good to change them fairly often.


Well-known member
Nov 26, 2007
I run an 9 temp range iridium plug in winter. Forget the actual name of it. 7 in summer. Barrels and barrels of c111/c12 through a 300 and 500. Have had zero fouls. Maybe you just had a bad one.
Premium Features