Plugs fouling

[glowa]

Its a 2019 850 with 42 hours, last year had a new software update, since new it is fouling plugs, on a good day 2-3 sets a day. I always replace both, because in the snow I am not willing to test which one failed.
I have a SLP exhaust, could this be causing this?

Yes, I just realized I am putting up with it for 42 hours, am I crazy or stupid?

Any help appreciated, of course dealer is useless in this 3rd world country

 

[o2bncamo]

There are a few threads here you can search and see if something works for you, I would try new plug caps, Different plugs NGK BR9EYA, Some people have had issue with the key (ignition) switch,
unplug it and use your kills witch for a day and see if the fouling goes away. If it does replace it with a new one.

 

[glowa]

my dealer just told me there is a new ECU version, I am surprised and I will try that first. Somehow I cannot believe that the only way to fix this is to change plugs!!

 

[TDR]

my dealer just told me there is a new ECU version, I am surprised and I will try that first. Somehow I cannot believe that the only way to fix this is to change plugs!!

Yep there were at least 2 ECU updates for 2019 850’s and the spark plug foul goes away. Been there done that.

 

[khamm2286]

I was fouling plugs last year and one of my injectors ohmed out bad, my coil packs were questionable on the tolerance but I replaced them too and all had been running really good. Dm me if you need those values

 

[Drnice]

Do I understand correctly that we are talking about the same problem as I have in the video? I have 54 hours now and I change the recommended spark plugs after each such case. The same thing happens with the spark plugs of the BPR 9 EYA, but after re-adding the thrust, everything works fine for a while. is it possible to solve this problem somehow? my dealer is powerless. (using translator)

 

[Spektaze]

Hey guys !

Same issue here with my 2021 khaos.

13 hours on it now. I’ve fouled 13 plugs on the PTO side.

I’ve tired BPR9ES, BR9EYA and BR9IEX

I ONLY have fouling on cold start. Always PTO side and I’ve tired long warmups, going as soon as cold goes out and going as soon as I’ve stated the machine. All foul.

For me it’s a consistent scenario, and here it is;

I put brand new plugs in the sled and it runs amazing. When the sled is running it runs AMAZING. I run for about an hour, come home and park the sled inside. The next day I come out. Start it, and it fouls PTO plug.. EVERY TIME. I replace both plugs, start the sled and again flawless. It seems like during the hour of use the plug is loading up on carbon (I ride trail, hills, mix of everything, I’m not gentle on the sled by any means). So when the sled is warming up on the 1 hour set of used plugs, she fouls. This happens every single time !!

To me it seems like a map issue and she’s very rich on the PTO side, maybe Polaris is running is rich to protect it. Never blown a plug on the other side.

Sled is currently at the dealer, I’ve had the reflash update and it did nothing.

I am not accepting trial and error, I paid $20,000 Canadian for this sled and it should be expected to work. We shouldn’t have to be doing this and doing that, the sled should work, period. Never seen something so unreliable. It’s very disappointing.

I’ll keep you posted.

 

[SlugExchange]

I had all the above issues, switched to:
NGK racing cables with tb05ema caps.
ngk bpr8es-6 gapped to .028. Dielectric grease on all ignition components.
Disconnected my key plug under the dash and run a magnetic Polaris tether.
No more issues

 

[MikeMetzger]

Not sure if anyone has mentioned it yet, but I found information that unplugging the ignition key fixed the issue for a lot of riders. I did it on mine after fouling one plug, no issues since....... ?‍

 

[G-Force]

Man I'm just knocking on wood, when I was in doing the SC on the 650 the other day, told my dealer that I was pleasantly surprised that I'm still on my original plugs ('19 RMK 850). I literally bought, and packed around, 6 new plugs since day 1, for no apparent reason.
Something of a unicorn perhaps, but I have no such complaints on plug fouling. Never any black streaks of exhaust, always starts pull 1 or 2, super pleased with it.

 

[208_RMK]

I ran into this issue a month ago (2020 RMK 850 155)- read on this forum to delete the TSS Throttle Safety Switch and plug in a bypass in it's place within the wire harness. I did this and never looked back. I run a durapro tether (I highly recommend). If you run a tether and actually use it properly the TSS is pointless really. Sled idles way better and is more crisp upon clutch engagement. Been looking at the plugs (often) and they are a lot cleaner no gunk. Got over 200mi no fouled plugs and several cold starts since. I think that switch makes the sled wayyyy to rich on idle and on a cold start its super prone to foul the plugs. I'd definitely try this if I were fouling plugs. The performance gain was awesome and it also stopped fouling plugs- win win imo.

FYI
I always run the stock NGK BPR9ES.
I also cleaned (blew out) the plug caps- A LOT OF DUST WAS IN THERE.
I never messed with the ignition (key switch).
Still run the standard kill switch as well.
Sled has 2900mi didn't start fouling plugs til 2600mi.

If you delete the TSS just take the throttle block a part remove the switch and chase the wire to the harness- that way it's easy to locate the plug for the bypass plug. Some guys leave the switch in the block and just unplug and tie up the TSS. I thought this was kind of lazy and just wanted it gone all together so I removed it completely.

Clean up the caps and delete that TSS- you can't just unplug it, needs a bypass plug with resistor. I bought mine $35.00 didn't hassle with making one. I guess a guy makes them on here for way less but I just wanted one so I bought the Force Turbo One. I'd pay it all over again for how much better my sled runs at idle.

 

[Ex-Flit]

I ran into this issue a month ago (2020 RMK 850 155)- read on this forum to delete the TSS Throttle Safety Switch and plug in a bypass in it's place within the wire harness. I did this and never looked back. I run a durapro tether (I highly recommend). If you run a tether and actually use it properly the TSS is pointless really. Sled idles way better and is more crisp upon clutch engagement. Been looking at the plugs (often) and they are a lot cleaner no gunk. Got over 200mi no fouled plugs and several cold starts since. I think that switch makes the sled wayyyy to rich on idle and on a cold start its super prone to foul the plugs. I'd definitely try this if I were fouling plugs. The performance gain was awesome and it also stopped fouling plugs- win win imo.

FYI
I always run the stock NGK BPR9ES.
I also cleaned (blew out) the plug caps- A LOT OF DUST WAS IN THERE.
I never messed with the ignition (key switch).
Still run the standard kill switch as well.
Sled has 2900mi didn't start fouling plugs til 2600mi.

If you delete the TSS just take the throttle block a part remove the switch and chase the wire to the harness- that way it's easy to locate the plug for the bypass plug. Some guys leave the switch in the block and just unplug and tie up the TSS. I thought this was kind of lazy and just wanted it gone all together so I removed it completely.

Clean up the caps and delete that TSS- you can't just unplug it, needs a bypass plug with resistor. I bought mine $35.00 didn't hassle with making one. I guess a guy makes them on here for way less but I just wanted one so I bought the Force Turbo One. I'd pay it all over again for how much better my sled runs at idle.

I am having the same problem on my 2021. It was cold in the snowies last week and I kept fouling plugs on cold start up and have to give it some throttle on warm start up. I am also having problems with idling and going into reverse, Otherwise it runs great. Where did you buy the TSS bypass kit. Thanks

 

[208_RMK]

I am having the same problem on my 2021. It was cold in the snowies last week and I kept fouling plugs on cold start up and have to give it some throttle on warm start up. I am also having problems with idling and going into reverse, Otherwise it runs great. Where did you buy the TSS bypass kit. Thanks

Here you go:

Force Turbos Throttle Safety Switch (TSS) Bypass

Force Turbos Bypass connector for Polaris TSS. This connector allows you to bypass the throttle safety switch in your stock thumb throttle. This product can be useful on its own, or if you are having problems with your stock Throttle Safety Switch. This product is for Polaris sleds 2011-2022.

forceturbos.com

 

[Spektaze]

Hey guys !

Same issue here with my 2021 khaos.

13 hours on it now. I’ve fouled 13 plugs on the PTO side.

I’ve tired BPR9ES, BR9EYA and BR9IEX

I ONLY have fouling on cold start. Always PTO side and I’ve tired long warmups, going as soon as cold goes out and going as soon as I’ve stated the machine. All foul.

For me it’s a consistent scenario, and here it is;

I put brand new plugs in the sled and it runs amazing. When the sled is running it runs AMAZING. I run for about an hour, come home and park the sled inside. The next day I come out. Start it, and it fouls PTO plug.. EVERY TIME. I replace both plugs, start the sled and again flawless. It seems like during the hour of use the plug is loading up on carbon (I ride trail, hills, mix of everything, I’m not gentle on the sled by any means). So when the sled is warming up on the 1 hour set of used plugs, she fouls. This happens every single time !!

To me it seems like a map issue and she’s very rich on the PTO side, maybe Polaris is running is rich to protect it. Never blown a plug on the other side.

Sled is currently at the dealer, I’ve had the reflash update and it did nothing.

I am not accepting trial and error, I paid $20,000 Canadian for this sled and it should be expected to work. We shouldn’t have to be doing this and doing that, the sled should work, period. Never seen something so unreliable. It’s very disappointing.

I’ll keep you posted.

Hey Guys,

Just an update.

Sled was at the dealer for 3 weeks. They could not find a single issue with it. Polaris weren’t any help either however they suggested using the NGK BUR9EQP platinum plug. They said the plug was not “foulable”

Got the sled back and fouled the BUR9EQP plug within 1.5 hours.

I’ve switched to the SLP plug wires and boots. I’ve also unplugged the ignition. Still fouling the BPR9ES.

Anyways sled is for sale now. I’m done with it, cutting my losses.

 

[Ex-Flit]

Hey Guys,

Just an update.

Sled was at the dealer for 3 weeks. They could not find a single issue with it. Polaris weren’t any help either however they suggested using the NGK BUR9EQP platinum plug. They said the plug was not “foulable”

Got the sled back and fouled the BUR9EQP plug within 1.5 hours.

I’ve switched to the SLP plug wires and boots. I’ve also unplugged the ignition. Still fouling the BPR9ES.

Anyways sled is for sale now. I’m done with it, cutting my losses.

did they ask you what oil you are running? the polaris dealer in Saratoga Wy. told me they had some machines that were running aftermarket oil and that was fouling plugs?? I ordered the TSS bypass switch but haven't had a chance to try it yet.

 

[Spektaze]

did they ask you what oil you are running? the polaris dealer in Saratoga Wy. told me they had some machines that were running aftermarket oil and that was fouling plugs?? I ordered the TSS bypass switch but haven't had a chance to try it yet.

They didn’t ask what oil I’m running, but I’ve been using Polaris oil that they recommended. Very curious with the TSS switch. If I still have the sled for next season I will be ordering one of these to try

 

[kanedog]

Its a 2019 850 with 42 hours, last year had a new software update, since new it is fouling plugs, on a good day 2-3 sets a day. I always replace both, because in the snow I am not willing to test which one failed.
I have a SLP exhaust, could this be causing this?

Yes, I just realized I am putting up with it for 42 hours, am I crazy or stupid?

Any help appreciated, of course dealer is useless in this 3rd world country

Are you crying foul? Hahaha

 

[Teth-Air]

On another forum guys have found that changing the coils fixes the problem. It is unclear if the probem actually resides in the wires or the caps but switching was the fix. These are the same coils going back years so finding a set to try should be relatively easy. My 2019 has been flawless but did run a bit fat with the early flashes. I ran hotter plugs for one season and it worked well. I know 2 guys who also were fouling plugs and went to 2 heat ranges hotter and now no problem. BPRES7 is what they used. I ran 6's but make sure you get a solid top or you will be cursing. It seems the coils (or associated caps and wires) are just providing a weak spark that allows for easy fouling. The hotter plugs resist fouling.
Polaris will not tell you it is okay to try different plugs but I do what works.

 

[DITCHBANGER]

BR9EYA great plug. Never fouled one. And not long ago my expensive diamond s can blew the bottom out so had to ride probably 20 miles with throttle wide open to barely keep moving as ecu was limiting rpm. But full oil and fuel going to engine almost emptied the oil rez anywho plugs were black and wet but never fouled. Poo850

 

[Ex-Flit]

Mine fouled plugs on very cold morning starts. In one week I changed 3 times in a row. On the 4th day I held the throttle open some and the sled started. has anyone else tried holding the throttle? My buddy said the fuel was running out of my exhaust