Cold start issue

[YamaMTX]

Hello Guys, I am looking for ideas on what to look for. Last year my nytro started fine all the time. At the beginning of this winter I went to start it and it turns over at about 250 to 280 rpm but doesnt want to fire. I believe you can smell a hint of gas after it cranks a bit. After cranking for a while and the rpms dropping to about 220 it will often fire. At this point it will fire and die, fire and die, after a few times of this it will start to run but it will have a bad miss. It will either die some more or start hitting on all cylinders. When the engine is warm it fires up with no symptoms and has good power. I have checked for codes and there isnt any showing. Changed spark plugs to brand new. Also added gas so it was fresh. Fresh oil change. Also tried a jump pack to make sure it was getting enough power. I tried cycling the key a few times before starting to see if it made a difference. So far everything I have tried hasnt made a difference at all. It seems like the colder it gets outside the more likely it is to not start at all. Looking for a place to look next or try. Thanks!

 

[74Nitro]

In diagnostics, is your coolant temp sensor reading correctly?

 

[YamaMTX]

In diagnostics, is your coolant temp sensor reading correctly?

It looked like it matched the temp outside prior to trying to start it yesterday so I would think it is working properly.

 

[Srxspec]

Have you run it enough to burn all the old fuel out? Sounds like a classic case of old stale fuel.

 

[YamaMTX]

Have you run it enough to burn all the old fuel out? Sounds like a classic case of old stale fuel.

At the beginning of the season the sled maybe had 3 gal of gas in it from last year. I added fresh until full. Because lack of snow I only rode it for 25 miles or so. I guess it is worth a shot to suck the fuel out and put in some fresh to see if changes anything.