Spark Plug Change - How Often?

[kidrman]

My 2020 850 Expert runs really well but the warmup idle seems like it has a miss, especially compared to my buddies 2020 SP. sled has about 800 miles.

Is it time for new plugs as a maintenance measure? I’m a middle of the spectrum rider so it gets ridden hard enough. Oil consumption is right where it should be.

Thanks in advance!

 

[Daner1978]

My 2020 850 Expert runs really well but the warmup idle seems like it has a miss, especially compared to my buddies 2020 SP. sled has about 800 miles.

Is it time for new plugs as a maintenance measure? I’m a middle of the spectrum rider so it gets ridden hard enough. Oil consumption is right where it should be.

Thanks in advance!

Plugs are cheap! I do mine every year. I highly recommend changing your plugs every year. What does it hurt? $60 is cheap preventative maintenance. Just make sure you index them correctly when you install.

 

[kidrman]

Plugs are cheap! I do mine every year. I highly recommend changing your plugs every year. What does it hurt? $60 is cheap preventative maintenance. Just make sure you index them correctly when you install.

Pretty much where I have been leaning. Didn’t think we needed to index these machines.

 

[summ8rmk]

Pretty sure ALL etecs must be indexed.

Honestly though, unless u ride Polaris 850 or 9r, plugs in modern day 2stroke snowmobiles should be good for 10k+ miles.

Sent from my SM-G998U using Tapatalk

 

[Daner1978]

Pretty much where I have been leaning. Didn’t think we needed to index these machines.

1000% you need to index them. If you don’t index them correctly…. You will not get the injector spraying the correct amount of fuel to ignite like it should.(Horrible bogs will let you know you are not indexed correctly) Good Luck fellow Sledder!

 

[Wapow]

The ones you get from a doo dealer are pre-indexed. Just tighten to spec. But it's a total PIA to get a torque wrench on em, so i still mark the gap side, to confirm they are oriented properly.

 

[kidrman]

The ones you get from a doo dealer are pre-indexed. Just tighten to spec. But it's a total PIA to get a torque wrench on em, so i still mark the gap side, to confirm they are oriented properly.

I would definitely mark them to make sure I am close.

Will buy from the dealer as well.

Thanks guys!

 

[1200]

Plugs wear and the gap will increase and be hard on the coil. Besides why not change them in your heated garage instead of on the coldest day in a blizzard . I've done it both ways heated garage is best.

 

[Coldfinger]

Is the gap supposed to face forward? I am new to these engines?

I have heard the plugs you buy from Doo will be correctly indexed once they are correctly torqued. I would like to know if anyone has tried plugs from the autoparts store, properly torqued them, and whether of not the gap was where it was supposed to be. I know you just dont want the gap facing directly away from the injector.

 

[simnil]

With the amount of oil these 850's chug they need plugs once a year.

As long as the back of the side electrode is at least 90 degrees away from the injector you are OK. (I.e, the side electrode should not obscure the spark from the spray from the injector)

Have been away from the 850 for two years now, have they fixed the indexing now? On all 600 and 800-E-tecs I have changed plugs on the indexing have been spot on, torque "right" and it has been fine. On the 850's I've changed plugs on they have been 100% wrong when torqued right. So the choice has been run the too loose or over torque.....

 

[Blk88GT]

Do you use the self fogging storage feature? If so you surely need a set of plugs.

 

[kidrman]

Do you use the self fogging storage feature? If so you surely need a set of plugs.

Yes I do. Sled is new to me this year but I bought it from my best friend and I know he uses the storage feature every spring.

 

[greenthumb]

The manual specs replacement on the turbos at 3000km and 10,000km for NA.
My experience is that all the e-tecs (800,850,850T) are due for a set of plugs in the 3500km range of mountain riding.
The sled may run fine, but the gap has usually opened up and there is a build up of crap despite being iridium. A rougher idle is usually the first indicator. I have not had an issue with the summarization feature ever.
FWIW, I just replace rather than clean and re-gap. Yes, indexing is required, but it is not complicated. Youtube it.
The rubber boot on the wire is a very tight fit; make sure the metal connector is fully seated. The wires are cheap. If there is any chafing or the connecter inside doesn't seat with a good 'snap', I would replace them too.

 

[Rick E]

...................... If you don’t index them correctly…. You will not get the injector spraying the correct amount of fuel to ignite like it should................

Incorrect spark plug indexing does not affect the injector spray pattern nor the amount of injected fuel.
It would affect the initial flash.


I agree..... mark the sides of the plugs prior to installing them.
Make the marks 90% away from the open electrode side (towards you) for better viewing.

 

[kidrman]

I replaced the plugs and the sled idles smoother and starts easier. Didn’t idle poorly or start hard before but felt like it could be better.

Indexing was no big deal but the price of those plugs… .

 

[klarkkentster]

I have a 2022 Turbo and a 22 Non Turbo I'm getting ready to change the plugs on - I'm assuming I need to take the hood off?

 

[TheBeattie]

I have a 2022 Turbo and a 22 Non Turbo I'm getting ready to change the plugs on - I'm assuming I need to take the hood off?

Yes, the hood has to come off. I found the turbo easier than the non. Take the turbo intake tube off and you can get a 3/8 drive ratchet in there with a proper plug socket. On the n/a sled it doesn't look like that's much of an option. And like others have said, mark the plugs for indexing, regardless of where you bought them. I found with the "OEM" doo ones I had to over tighten a little to get them 90 degrees to the injector