Fouling spark plugs on cold start
- Thread starter HpPerformance
- Start date
If it is leaking, that cylinder should be full of fuel. If he tried putting new plugs in before he tried starting it and it still fouled then it would be obvious that it is not the carbon build up on the plugs.
D
Per Indy specialty starting procedure
Start sled
Let idle to 100 degrees
Do not hit the gas at all
Turn off sled
Let sled sit min 5 minutes to heat soak
The motor and get all aluminum up to
Equal temperature
Restart sled
Let temp hit 100 degrees and take off
This is a cold start procedure
1st start of the day
I do this religiously every day and never
Had any problems
It’s sometimes a pita waiting
Just my 2 cents worth
Start sled
Let idle to 100 degrees
Do not hit the gas at all
Turn off sled
Let sled sit min 5 minutes to heat soak
The motor and get all aluminum up to
Equal temperature
Restart sled
Let temp hit 100 degrees and take off
This is a cold start procedure
1st start of the day
I do this religiously every day and never
Had any problems
It’s sometimes a pita waiting
Just my 2 cents worth
Good to see Polaris still has the same issues with this that we did with our Polaris sleds from 30 years ago. It seems like their fuel mapping and ECMs still need work.
It's 2022 and Polaris owners still have to carry many extra sets of spark plugs and use a "Indy specialty starting procedure."
It's 2022 and Polaris owners still have to carry many extra sets of spark plugs and use a "Indy specialty starting procedure."
K
I fixed my fouling plug issue by switching both sleds to Ski Doo - problem solved.
No plug fouling on mine or buddies 850's. Had 2 plugs physically break though..weird. But always do not touch throttle till 100-110f during warmup, even after a quick snack. My Poo(1st one) was a great sled, wish Poo had a SHOT start system.
You gotta think Poo is trying to come up with a lighter-weight starting system, like SHOT. They could use a lithium-ion battery that would start the sled after the first pull in the morning. Would probably save at least 10 pounds.
Not sure if you could get any lighter than SHOT, but it'd be nice. The trouble with anything using a traditional starter is you need a (relatively) heavy motor, which probably weighs more than the whole SHOT system. I suspect the breaking plugs problem is more NGK's fault than Polaris's. They shifted manufacturing facilities for their general market plugs, and either had a run of bad ones, or they're a little too much on the fragile side now.
The Indy Specialties starting procedure, or a similar, dutifully followed starting regiment, isn't necessary to prevent premature failure, but would probably extend the life of any sled. It doesn't have anything to do with plug fouling, it's to bring the engine fully up to temperature and help stabilize the cooling system. You want the block to be fully warmed up (just waiting until the coolant hits a certain temp won't cut it), and you want to cycle the dead-cold water out of the heat exchangers.
For whatever reason, Polaris does seem to have more issues with things like cold, and even warm starts, but it's hit or miss. In my case, cold starts take several pulls, and it wants to flood on hot starts if you don't give it a hearty pull. That's on a Pro, but it seems typical of the sort of issues that still exist on some new sleds. But on the other hand, most 850s have never fouled a plug: I've rode with a half-dozen or so 850 owners, and none had or complained about starting issues. With the real problem sleds, guys either hound the dealer until it gets resolved, or find a workaround (often cracking the throttle while you pull does the trick). The reason we "put up" with it is, well, a lot of people have no problem, and even for many who do, it's worth it to ride arguably the best chassis. I suspect the bean counters just have too much power, so you end up with stupid little things (like unsealed relays, skimping on other components that could be causing impossible-to-diagnose issues). It's pretty rare for there to be no fix, and in the long run it's kind of a wash. Look at Doo: much harder to service and more complex; Cat: similar fit and quality issues, only it seems to cause more catastrophic failures (snow ingestion failures on Ascender, for instance). In the end, there is no perfect choice, and every sled is going to break down or fail sooner or later. It's all about what you like to ride and what's most important to you.
The Indy Specialties starting procedure, or a similar, dutifully followed starting regiment, isn't necessary to prevent premature failure, but would probably extend the life of any sled. It doesn't have anything to do with plug fouling, it's to bring the engine fully up to temperature and help stabilize the cooling system. You want the block to be fully warmed up (just waiting until the coolant hits a certain temp won't cut it), and you want to cycle the dead-cold water out of the heat exchangers.
For whatever reason, Polaris does seem to have more issues with things like cold, and even warm starts, but it's hit or miss. In my case, cold starts take several pulls, and it wants to flood on hot starts if you don't give it a hearty pull. That's on a Pro, but it seems typical of the sort of issues that still exist on some new sleds. But on the other hand, most 850s have never fouled a plug: I've rode with a half-dozen or so 850 owners, and none had or complained about starting issues. With the real problem sleds, guys either hound the dealer until it gets resolved, or find a workaround (often cracking the throttle while you pull does the trick). The reason we "put up" with it is, well, a lot of people have no problem, and even for many who do, it's worth it to ride arguably the best chassis. I suspect the bean counters just have too much power, so you end up with stupid little things (like unsealed relays, skimping on other components that could be causing impossible-to-diagnose issues). It's pretty rare for there to be no fix, and in the long run it's kind of a wash. Look at Doo: much harder to service and more complex; Cat: similar fit and quality issues, only it seems to cause more catastrophic failures (snow ingestion failures on Ascender, for instance). In the end, there is no perfect choice, and every sled is going to break down or fail sooner or later. It's all about what you like to ride and what's most important to you.
Been doing almost this very thing since 2011 with my first PRO. Never fouled a plug one until I started having issues with my 20 850. Had to unplug the fuel pump trick when putting it away. Later figured out that the map was a bootleg one from SLP and not the correct one for the twins on it.
Flashed the correct map on it and rebuilt the top end (scarred piston, probably the main culprit to starting issues) and it has ran like a champ ever since. Occasionally use the fuel pump trick if it doesn't start on the 3rd pull cold. That works every time.
Adjust your throttle cable. I have a 2019 850 SKS and have only killed on plug within 6200 miles. Blown a topend tho and crank bearing failure.
C
The key switch stopped my 2019 with unknown ecu flash from starting reliably. Unplugged it and it starts every time now. 2019 w/ boondocker sidekick turbo.
Check your wires and caps also.
Check your wires and caps also.
2020 850 that I have run with both the SLP can and GGP trail can. Lucky for me I have never had an issue with fouling plugs on a cold start. My cold start startup procedure is a little bit different. As soon as it starts usually on the second or third pull I immediately given it throttle and bring RPM right up to the point of clutch engagement for 3 to 5 seconds and then let it come back down to idle and then rev it a few more times back up to clutch engagement and then it seems to idle perfectly and warm up without loading up or struggling to stay running and wanting to stall. No problems. Purrs like a kitten while I gear up and enjoy the beautiful sound and the sweet smell of two-stroke. I only hope the good luck continues.
U
I just picked up a 21 Khaos with a brand new dealer installed top end. Same thing. Did a break in road ride where I was really gentle on it. Wondered if I would foul the plugs. When I went to load the sled out of the garage and onto the deck the next ride it ran like ****. Sounded like it was running on one cylinder. Changed the plugs and ran great the rest of the day. Went to unload it and ran terrible wouldn’t go into reverse. Got it off the deck and ran it up and down a friends driveway and it seamed to clean up.
Next ride on cold start in the morning it wouldn’t go into reverse again and sounded like it was running on one cylinder. Idling around 13-1400 rpm. Changed the plugs again. Ran good most of the day.
I did have a few bogs but it was crazy deep. Could have been plugged exhaust or intakes. But would clear up and run good once I got moving again.
Next ride for the first start of the dayI tried pulling it through a few times with the kill switch in and holding the throttle wide open. Started up fine and ran strong all day.
I went away for work and have not got another ride in yet. I did add some oil to the gas tank for the first ride. Dealer did not put the sled in break in and didn’t say if they added oil. I just did it as a precaution.
To me it looked like it fouled the PTO side plug both times. Also the sled seems to need a bit of throttle to start when warm.
mine did the same thing as above, but only on extreme cold days (4 days in a row) below zero and only first thing in the morning. on the last day we held throttle open a little bit and it did not foul plugs. I am disconnecting the tss and going to give it a try as per someone recommended, once my back feels better
U
Well sled is still fouling plugs. I was riding during a recent cold snap. Snow was terrible. We rode a couple new areas. So a lot of cruising around trying to find our way to places. So really not riding that hard. Mostly part throttle operations all day.
Both days on the trail ride out, fouled the PTO plug. Cruising down the trail and go to give it some throttle and it was running on one cylinder.
Sled still bogs in the really deep.
The girlfriend rides an almost identical sled, definitely does not ride as hard. Way less full throttle operation. Fouled one set of plugs in more km of riding time.
Both days on the trail ride out, fouled the PTO plug. Cruising down the trail and go to give it some throttle and it was running on one cylinder.
Sled still bogs in the really deep.
The girlfriend rides an almost identical sled, definitely does not ride as hard. Way less full throttle operation. Fouled one set of plugs in more km of riding time.
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