This is probably a stupid question but I am a newbie, so here goes. I bought new plugs the other day for my 97 670 and I was figuring that they didn't come pre-gapped. So I was wondering what the Gap should be for a set of Br9es? Thanks for your help http://www.snowmobileworld.com/forums/iB_html/non-cgi/emoticons/smile.gif

Word has it that all Doo's should be gapped at .018" for best results.

They have changed the spec from .018 to .020 for the 02 MXZ 800. Can't let that .002" get away from us. Tailgator is right on all the others though. They are .018.

For the BR9ECS plug that the MXZ800 takes the reccomendation is that you do not try to adjust the gap at all they come pregapped. *Is that why they are $6.00 + a plug?

The 2 I bought were not pre-gapped to .020". Who told you they were pre-gapped? The ones I bought were at about .028".

It took me a while to remember where I saw that statement myself and with a little digging I found it. *If you have a copy of the December 2001 issue of SnowTech it's on page 12 under Ski-Doo Spark Plug Substitutions (2nd paragraph). *I checked them as well to be sure, all 4 I bought were set at.018"

The br9ecs that I got were open quite a bit had to tap them a bit to get the gap down to .018,now your saying they should be .020 I hadn't heard that one yet!

Where did you hear that they should be set at .020"http://www.snowmobileworld.com/forums/iB_html/non-cgi/emoticons/confused.gif *I have been running mine at .018" on my 02 MXZ800 with no problems yet. *Not that .002" is going to make a difference, just wondering.

TailGater, the .020 spec. is right out of the *Ski-Doo owners manual. *Idooski has read the manual. Yes .018 for all other sleds other than the 2002 MXZ 800 with the expensive plugs.

Thanks for the info! *Just goes to show ya it does pay to read that stuff.

Just looked at the spec in the manual and your right it does say .020", but the factory sticker on the PTO side of the cylinder head of the engine says to set it at .018". *Any ideas? * http://www.snowmobileworld.com/forums/iB_html/non-cgi/emoticons/confused.gif

Since this post is regarding a 97 670, here`s my opinion...run the largest gap it`ll take without mis-firing or fouling. I run my 583 and 800 3x3 at about .025. The dfference? Drivability for lack of a better description. Motor seems to pull better in the mid range. The reason? If you think about it the bigger the spark, the easier it is to ignite the fuel/air mixture. I`m pretty hard on my motors and have had no adverse effects from doing this. Just my .02