2018 Axys 800 spark plug issues.

[Tchetek]

18 Axys 800 continually fouls a plug. Always PTO side. Almost one per ride.

I plan on checking the TPS and the spark plug caps and wires.

Any other thoughts on what I can check?

Machine runs pretty cold up in the hill. Maybe 30 degrees c. Anyone using a little hotter plug. BRP8es?

 

[Rhodesie]

new to you sled or had it from new? give as much info as possible. i know its a lot of blah to type but the more info the better.
fuel, time of day, warm up, during the day, exhaust type, crap like that. you should be seeing 99 to 110f in powder. 87f is really cold.

 

[Tchetek]

new to you sled or had it from new? give as much info as possible. i know its a lot of blah to type but the more info the better.
fuel, time of day, warm up, during the day, exhaust type, crap like that. you should be seeing 99 to 110f in powder. 87f is really cold.

Had sled since new. 2200 km ish.

It has always done it since new. Originally figure rich from break in cycle. But might be happening more often now. But it’s been only the PTO side for probably the last 10 plugs.

Motor stock, exhaust stock, usually happens halfway through the day or later,

Both during riding and last one was after it was shut down for a break. Only fired one cylinder,

And ya it might be running closer to the 99-110 in power. Don’t look at the gauge too often but recently accidentally switch it to metric.

 

[gedakbx]

i would try BRP8es or Br9 eix / Br8 eix iridium plugs. My 2020 850 had no plug issues with the stock plugs, my new to me 2021 850 fouled one in the garage yesterday so it is probably getting 8 heat range plugs in it.

 

[Tchetek]

I was thinking of trying that after checking the TPS,

Any concerns with being too hot? Or how to tell if it is without doing any damage?

 

[gedakbx]

doubt one heat range will be to hot, good old plug check i guess. Mine were black not tan. we shouldn't be having plug issues on EFI sleds IMO

 

[Rhodesie]

try one range hotter plug. take the plug caps off the wires and cut a bit off each wire. put some dielectric grease on the wire and screw the caps back on. try switching caps from side to side. brake clean out the caps and put a small amount of grease on the top of the spark plug before installing the caps. try this before adjusting the tps. i would think if it was out of range it would foul between the two. check the wiring plugs goin to each coil and put a little grease in them as well. put some seafoam in the fuel tank before next fill up to get a good mix. keep us informed.

 

[Modman]

I was thinking of trying that after checking the TPS,

Any concerns with being too hot? Or how to tell if it is without doing any damage?

You can tell the heat range will be correct by how many threads down the plug body the colouring goes. Correct heat range should be 1 to 2 threads down. If it goes farther then its getting too hot. You want to clean it off with solvent or brakleen, get the oil off. You are lookin for the metal discoloration but don;t use it as gospel. 1 or 2 threads more might be just what you need. But since its consistent to the PTO side, I think you have an issue there, its not likely a heat range issue. Check wiring and resistance. And run some injector cleaner through the tank as suggested, and maybe pull pipe and look at exhaust valves and make sure both look similar.

 

[TDR]

I can almost guarantee it is the TPS. I snowchecked two 18’s and they both had this problem. One of them had a bad TPS which was replaced and the other had one that needed to be reset. The first 1.5 years were a nightmare. Fouled so many plugs it was nuts. The folks at Cycle Works West were finally able to help me figure this out and correct the problem.

 

[Tchetek]

I can almost guarantee it is the TPS. I snowchecked two 18’s and they both had this problem. One of them had a bad TPS which was replaced and the other had one that needed to be reset. The first 1.5 years were a nightmare. Fouled so many plugs it was nuts. The folks at Cycle Works West were finally able to help me figure this out and correct the problem.

That’s where I am gonna start. As well as check my wires and caps.

Was your consistent to one side? PTO?

 

[Tchetek]

Had sled since new. 2200 km ish.

It has always done it since new. Originally figure rich from break in cycle. But might be happening more often now. But it’s been only the PTO side for probably the last 10 plugs.

Motor stock, exhaust stock, usually happens halfway through the day or later,

Both during riding and last one was after it was shut down for a break. Only fired one cylinder,

And ya it might be running closer to the 99-110 in power. Don’t look at the gauge too often but recently accidentally switch it to metric.

I reread your advise and will be servicing all the plug connections as suggested. But will probably check tps as well

To answer your other questions/suggestions,

It got sea foamed liberally before storage and again before the last trip. (First ride of the season)

Old fuel was pumped out and fresh (supposably non ethanal) shell premium and a 1/4 can of sea foam to start the season.

Probably happens more often after lower/midrange throttle usage.

Next rides will prob be in the new year.

Merry Christmas to all!

 

[OnlyPolaris]

your sled is running way to cool. should be around 45-50 c usually. i would think your thermostat is stuck open. i have never in my life fouled a spark plug. going on 2600km on my 18 sks.

 

[SUMMIT TREE]

Heres some plug wires I had issues with on my Doo.
Visually looked ok externally but ohm meter showed very high/ open.

Bought all parts for MSD Wires off AmAzon and made my own.

 

[skidoo6100]

Change your thermostat.

 

[banditpowdercoat]

I just changed my factory plugs in my 18 Axys. 3000Km on them when finally fouled one. Wanted to see how long they would go. So something amis with yours for sure. Also, My T stat keeps her 97-103F in powder all day long.

 

[SUMMIT TREE]

I remember one time on my 800 Etec, we were changing plugs chasing a problem.

Put the old plugs in the boots and pulled it over, gave a weak orange spark.

Tried a new plug same thing, it was a HUGE difference. Like a powerful blue/white bolt of lightning. I couldn’t believe how much difference there was.

 

[TDR]

That’s where I am gonna start. As well as check my wires and caps.

Was your consistent to one side? PTO?

Yes it was consistent to one side and a real pain. Once you get the TPS figured out change the spark plug boots because all the taking them on and off makes them looser on the top of the plug and they start arcing and forming carbon which makes weak spark. And here I though I was the only one to get 18 lemons! Still have one as a backup sled and runs mint now.

 

[Tchetek]

try one range hotter plug. take the plug caps off the wires and cut a bit off each wire. put some dielectric grease on the wire and screw the caps back on. try switching caps from side to side. brake clean out the caps and put a small amount of grease on the top of the spark plug before installing the caps. try this before adjusting the tps. i would think if it was out of range it would foul between the two. check the wiring plugs goin to each coil and put a little grease in them as well. put some seafoam in the fuel tank before next fill up to get a good mix. keep us informed.

Do the spark plug wires separate from the coils. I bought new caps and a chunk of wire but Manual saying wires are not serviceable?

 

[Tchetek]

Thinking it’s a wire/cap issue…. I’ve been zapped a couple times through the rubber cap and a glove when pulling the wires off to figure out which side lost the plug.

 

[Tchetek]

So far I checked the TPS to start. My idle was pretty low and was cheating it with the throttle free play adjustment in the cable.

It didn’t seem too far out from spec.

Before adjustment
Idle 9.29
Throttle plates full closed 7.26