My 05 SP500 H.O. wont idle when the temps are below 10 degrees F. If I keep on the throttle its fine, but as soon as I let off it croaks. It works fine when temps are warmer. I live in ND so I need to run it in the cold to plow the snow. Im thinking I may have to rejet. I dont want to run the engine lean and burn it up. Any suggestions before I tear the carb off? Thanks.

 

Will it idle with the choke on?

 

Full choke, cold engine. yes. Half choke with warm engine, nope

 

Sounds to me that you not getting any fuel at idle. Your air/fuel screw maybe needs tuned. Changing your main jet only effects 3/4 to full throttle so that wouldn't help you.

 

Can't help with a solution, but I can tell you I've been plowing with my 2004.5 500 H.O. in -25`C or between -10 to 15F and it starts and runs fine. It's not parked in heated garage. I just pull the choke to start it, then as it idles I keep pushing the choke in and it idles perfect. Are Canadian models jetted any different? My dealer told me I didn't have to re-jet for winter.

 

How much throttle do you need to keep it running?
Can you make it up with the idle speed screw?
You may have to richen your air mixture screw for cold weather operation

 

I looked in the owners manual and the machine is jetted for temps above 40F. It does specify a different jet for temps below 40. 155 for 40 and above 160 for lower.

 

Jutst a little throttle will keep it going. I will try adjusting the idle up a little and see if that works. I will check the plug too for color and see if its running too lean. Thanks.

 

I would try some isopropyl in the tank...sounds like you might have some moisture in there and freezing up a bit.

 

WOW...Mine just did the same thing today.....first time I got to use my new Glacier plow setup. This sp500ho (2004.5) has run like a swiss watch until today. Plowing and it would not idle without stalling and backfiring through the exhaust when rpm's were raised. Called dealer..he advised that it was either a speck of dirt in the carb or water in the gas.
I added dry gas...thinking that sitting in my garage for the last month might have contributed to condensation in the tank. After about 5 minutes of nursing the throttle, it seems to be MUCH better.
Maybe I got lucky? lol