cold start pops and sputters and almost stalls

[Ernie]

My new 1500 Northstar runs terrible when cold starting. I let it idle for awhile, then try to start going in comfort mode and it pops, backfires shudders and almost stalls. Is this normal? I have many fuel injected machines, including Polaris 4 wheelers that don't have this problem. Or am I being picky? After the engine warms up to operating temperture the problem goes away.

 

[Clubin]

Cold start being what? -30c?

 

[Mr.C]

My new 1500 Northstar runs terrible when cold starting. I let it idle for awhile, then try to start going in comfort mode and it pops, backfires shudders and almost stalls. Is this normal? I have many fuel injected machines, including Polaris 4 wheelers that don't have this problem. Or am I being picky? After the engine warms up to operating temperture the problem goes away.

What type of fuel are you running? If you’re running non-ethanol fuel, try switching to normal pump gas with ethanol. I know it sounds weird, but I was running non-ethanol 92 octane. Switched to 89 octane ethanol pump gas and problem went away. My dealer suggested it, and he wasn’t wrong. In the summer time I wasn’t having an issue. Only in the fall/winter where the temps were in the 20’s overnight.

 

[Ernie]

Wow, I am running non-ethanol 92 octane fuel. The stealer said to use high test,but nothing about the blend. Thanks for the tip.

 

[Big Red]

I run 91 non ethanol in all my toys and small engines and have never had a problem with anything I have ever put it in. You can try to run ethanol to see if it works but it's never been a solution for me.........rather the problem.

 

[Mr.C]

I run 91 non ethanol in all my toys and small engines and have never had a problem with anything I have ever put it in. You can try to run ethanol to see if it works but it's never been a solution for me.........rather the problem.

I’ve always done the same without issue. In my ‘20 XP 1000 it would do it when it was super cold. Even had fouled plugs in it once. Then when my XD started doing it I mentioned it to my dealer and he asked what I was using for gas. I told him, and he said try switching and see what happens. I bet it goes away. So far it has, so…This right towards the end of actual winter, but still some cold overnight temps and so far no issue. I’ll see what happens over the course of a full winter.

 

[Jerem62]

I was having the same issue with 91 non ethanol. Switched to 93 with ethanol and no longer an issue for me.

 

[oneal]

If you research ethanol some of the opinions and feelings are as strong and deep rooted as political beliefs.
I do know when it was first introduced my two strokes had issues so I still avoid it in them and only race gas in my Montessa.
Bur have a ten year old Pioneer with 1200 hrs, numerous different Polaris products, couple of V twins on mowers and a blower all drink ethanol with no issue. I don't remember the last time I purchased a spark plug.

 

[Big Red]

I had a 22 HP Kohler in a riding lawnmower (that was new) that would not stay running and when it did it was rough. Called the manufacturer and they asked me if I had ethanol in it, which I did, they told me to drain it and use regular gas which solved the problem. I had a similar issue with a 2001 Victory motorcycle which is when I decided to only run premium gas in all my small motors and toys and never had an issue since. That said, that's been many years ago and a lot has changed with both motors, fuel systems, and fuel. I know you can run 10% ethanol in almost anything made today and should not have any problems at all. I run 15% ethanol in my truck (because it's the cheapest) and it works fine other than it does not get as good as gas mileage or have quite as much power (per manufacturer) as it does running the "good stuff" I know I could probably do just fine with ethanol in my toys but I'm old and stubborn so I'm still going to give my small engines and toys premium gas whenever I can get it.

 

[Twrman 77]

Higher octane gas combusts at a higher temperature that is why lower octane gas works better in cold temperatures. I had the same issue and my dealer told me to switch from 91 Premium fuel in the winter to 87 (with or without ethanol).
The other advice I received was to turn the key to On and wait 5 seconds or so before cranking to start. Mine would surge constantly between 1000-2500 RPM until it got warmed up. This has made a significant difference. I get in the habit of turning on the key and getting my seat belt fastened and ready to go before cranking it over and have found it works better for me.

 

[Big Red]

What does waiting 5 seconds gain you? Is it just to make sure the fuel pump had time to complete it's cycle?

 

[Twrman 77]

Yep I thought the same thing but it has made a difference on my machine. It doesn’t surge when idling when it’s cold.

 

[oneal]

Yep I thought the same thing but it has made a difference on my machine. It doesn’t surge when idling when it’s cold.

Must not be typical to all, mine doesn't surge or pop. Been drinking ethanol since day one.

 

[Big Red]

No surge, no hard starts, no rough idle, no issues with running 91 octane. She just starts and goes as one would expect.

 

[LowlyOilBurner]

What type of fuel are you running? If you’re running non-ethanol fuel, try switching to normal pump gas with ethanol. I know it sounds weird, but I was running non-ethanol 92 octane. Switched to 89 octane ethanol pump gas and problem went away. My dealer suggested it, and he wasn’t wrong. In the summer time I wasn’t having an issue. Only in the fall/winter where the temps were in the 20’s overnight.

Yep. Same deal on the Xpedition’s. I ran a blend of 87 mixed with 90 non ethanol and never had an issue. Guys running straight hi test in Xpedition’s complained about the same thing in colder temps. Hard starting too. I just run 87 in the XD. Definitely weird, seeing as I had banshees that I had to run VP 112, and an RMax 1000 that needed 91. I too run non ethanol in everything from my Stihl equipment to my generators to my Honda HRC216 push mower I use for mowing the trim around my property. Sleds get the same treatment too. I guess they just pull a lot of timing out of them to prevent knock?

 

[Mr.C]

Same here. I still plan on running 92 octane non ethanol in all my other small engines like I’ve been doing for years. Whats weird is I didn’t have an issue with my 2019 sportsman xp 1000, just my 2 rangers.

 

[Clubin]

Higher octane gas combusts at a higher temperature.

Sorry couldn’t leave this info. It’s incorrect.

No, higher octane gasoline does not burn hotter. Instead, higher octane fuel is designed to resist premature ignition or "knock" in engines with higher compression ratios or those that use forced induction. Lower octane fuel burns more quickly, while higher octane fuel burns more slowly, allowing for controlled combustion in high-performance engines.

Fuel with an 87 octane rating burns more quickly while higher-octane fuels burn more slowly. In engines designed for standard unleaded fuel, efficiency and performance is optimized for 87 octane and could actually perform worse with higher-octane fuel since the burn rate is slower.

 

[oneal]

Higher octane gas combusts at a higher temperature that is why lower octane gas works better in cold temperatures.

No, higher octane gasoline does not burn hotter. Instead, higher octane fuel is designed to resist premature ignition or "knock" in engines with higher compression ratios or those that use forced induction. Lower octane fuel burns more quickly, while higher octane fuel burns more slowly, allowing for controlled combustion in high-performance engines.

I think you are both saying the same thing.

 

[oneal]

Definitely weird, seeing as I had banshees that I had to run VP 112,

I had a couple and remember them so well. I mixed mine with Blendzall for no good reason, just loved the smell. One of the many toys I wish I still had sitting around.

 

[Big Red]

While the feel of many of the above statements may be correct there are some inaccuracies.

1. Higher octane gas does not burn hotter than lower octane gas, and lower octane gas does not burn cooler than higher octane gas.
2. Lower octane gas does not ignite better in colder weather than higher octane gas. They are both designed to ignite when given a spark.
3. I did not find any mention that higher octane gas burns more slowly than lower octane gas, nor did I see where lower octane gas burn more quickly.

Higher octane gas simply makes the gas more stable and less susceptible to pre-ignition. In higher compression engines lower octane gas can combust early before the spark plug is fired and the piston is in position for the power stroke part of its cycle. A higher-octane rating means the fuel is better balanced and stabilized against spontaneous combustion, which can cause knocking and damage to a car engine.

This octane thread is almost as fun as the oil threads on motorcycle forums