Snowmobile spark plugs?????

[GummyMonster]

Morning,
Hoping to get some good advice.
I recently picked up a 2006 ski doo Expedition 600 sdi h.o.
It has Extremely low km's for the year, and looks like new.
I have to admit my snowmobile knowledge is limited. I rode some about 20 years ago (Holy kerfrick im gettin old!!!) And we always replaced parts in kind.
So here is my question : on different forums various guys say to use BR8 plugs (stock). And some say BR9's are best,but don't say why.
If you don't mind explaining,what is the reason for hotter or cooler plugs. I will be using around Dunvegan area, so no BIG hill climbing,mostly stop and go to check a few traps,and pulling the kids around on sleds and such.
Thanks' in advance for your time,
Ken

[Kim473]

Stick with the colder plug so you don't burn a hole thru the pistons on warm days. JMO. I used to use hot plugs and 1/2 aviation fuel as I liked performance ( raceing ) but had to replace many pistons because of that. In the winter time aviation fuel had a octain of 110 at that time so 1/2 av gas and 1/2 #1 gas would give a octain of about 100 to 105 .

[Ice Fishing Maniac]

What does your manual say to use for this sled?? That's what I would use.

There are different versions in the same size (Example: BR9ES / BR9EV / BR9EVX). Some plugs are platinum tipped, or other design for performance

Depends on performance you want and how much you want to spend.

If you model says to use BR8ES or 9ES, and its not a performance sled, save your $$$ and use them.

For me my sled had BR9ES but I run the BR9EVX for better performance as the motor is done up. I also find less plug fouling with the better plugs when in deep snow.

[Sooner]

I have been a ski doo guy forever, stick with the plug the manual/dealer says to use. Thats what my friend who is a bombardier mechanic says. Designed to use a specific plug for that specific engine kinda thing.

[Hevishot]

Run the stock BR8 Plug. If your not high marking or holding it wide open for days I would not worry about burning holes in pistons on a stock unit.

[artie]

way back when I had a skidoo silver bullet we would put the plugs in the oven and heat them up then quickly put then into the machine to get it to start. I sure hope you do not have to do that with the newer machines.

[dumoulin]

Always use what the manual says. Engineers spend their whole life figuring this stuff out. Keep everything OEM. The minute a guy messes with this stuff, it almost always ends up in premature failure of another part.

[GummyMonster]

Thanks' guys.

[fordtruckin]

Always use what the manual says. Engineers spend their whole life figuring this stuff out. Keep everything OEM. The minute a guy messes with this stuff, it almost always ends up in premature failure of another part.

Yup, especially with how technically complex things are getting these days. I always use OEM if possible!

[northerngmc]

The early 600SDI's, 04 and 05 had problems with spark plugs fouling. The solution was to run the hotter plug.

I had an 05 GSX with the 600SDI and the it always ran BR9's in it and it ran fine. One year the dealer replaced the plugs with BR8's, as per factory specs, and I spent a year trying to figure out why it was fouling plugs. It probably fouled a plug every couple of rides. It would do it on start up and then run on one cylinder. I put BR9's back in it and did not have a problem.

By 07 SKIDOO was putting BR9's in all there 600SDI engines.

I also had an 08 Renegade with the 600SDI and it ran BR9's from new.

So go ahead and go back to BR8's if you want, but if it starts fouling plugs switch to BR9's.

Have fun riding.....

Dootalk.com is a great resourse for Skidoo's. Lots on there on this subject.

[jim summit]

Just to clarify, the BR9 is a cooler plug then the Br8.

Lower the number, hotter the plug.

Running to hot a plug will cause detonation.
Plug stays hot enough to light the fuel before the plug fires.
Result is a hole in the piston.

[northerngmc]

Just to clarify, the BR9 is a cooler plug then the Br8.

Lower the number, hotter the plug.

Running to hot a plug will cause detonation.
Plug stays hot enough to light the fuel before the plug fires.
Result is a hole in the piston.

I agree, my mistake. Yes first years 600SDI had BR9 and then went to BR8.