in the last couple of weeks my '03 sp500 wont start if the temp drops below freezing. i have never had this problem before. i'm in mississippi and we dont get a ton of cold weather but last year got into the teens some and it started fine then, and was starting fine earlier last month when it was below freezing. above 40 degrees it starts fine and between 32-40 it starts hesitantly and it will stay running only if i keep it choked or if i keep the throttle depressed but as soon as i let off the throttle it dies (even if been running for several minutes). changed plugs, didnt help. changed gas, didnt help. changed fuel filter earlier this year. i have tried starting it with varying degrees of choke and doesnt help. it turns over, but just wont crank, sounds like its not getting gas, but what i dont understand is when it finally does crank(once the temp warms up enough, and i keep the throttle depressed to keep it running, why it dies as soon as i let off the throttle. i even tried starting it in my garage before i leave to go hunting and letting it run for a few minutes, but after towing it for 50 minutes in sub freezing temps, it wont crank when i reach my land. any ideas? is there some type of sensor that deals with cold weather starts? any help would be greatly appreciated, thanks.

 

maybe you need a carb clean u jack ****

 

Hey polaristb250 try and lighten up a bit. Are you having a tough day? You’re correct in your statement but JackStraw is asking for some help not to get his head bitten off.

 

your machine needs this update, page 1
page 2

print it out and bring it to a GOOD dealer and they SHOULD do it for free, I had mine done at no charge at a dealer that DIDN'T sell me the quad. let me know if you need any more details.

oops, just reread and saw you have a 500, sounds like you need to richen up anyway, start with the pilot jet, maybe one size up, and see of it will start and stay idling. while you are in there, clean her out real good with carb cleaner. easy and cheap job, you can do it.
peace

 

i'll try the carb cleaning, but zerowick, is there any reason why i should have to adjust the jets if it was working fine last month in the sub freezing weather? in three years i have never had any problems with cold starts. plus we dont get a ton of cold weather down here so i hate to have it set up for cold weather when most of the use will be in hot weather. do you guys run in gas additives in your bikes? the only thing i put in is some stabil when i know i wont be riding it a lot.

 

Hi, I see you have a 500 HO. I have a Scrambler 500, which I believe has the same engine. Mine had problems starting in cool/cold weather. It had gotten so bad that eventually I had to turn up the idle on it for 10 minutes otherwise I couldn't let go of the throttle or it'd die once it did start. I did the usual stuff, too, new spark plug (more than one, lol), checked out the coil/wiring, choke setting/adjustment, filters, fuel treatments, etc., etc.
In the end, the thing that fixed it was adjusting the valves. The rockers to the intake valves actually weren't fully releasing off the intake valves all the way. Once it warmed up, the rockers apparantly would loosen up a bit on the valves as the engine ran normal, but cold it ran like crap and was very hard to start, lol. Go ahead and take off the rocker cover and check out the clearances and see if they're off...

 

not really. perhaps you just have some gunk in there, take the bowl off, take the pilot jet out and spray it off with carb cleaner, do the same with the main and spray the float hinge too. don't be shy with the cleaner. make sure your air filter is clean and nothing is blocking the intake snorkel.

peace

 

temper50 is right , I just went thru the same thing with my wifes 2004.5 sportsman 500.
Everything pointed to carb problems, but after going thru the carb new plug filters and so on I found the intakes were tight, holding the valves open a little. after setting the valves it runs great, it even has a fast idle with the choke on again. If you do have the carb off drill out the brass plug that covers the idle mix screw. it will idle much better if you richen the idle , I set mine 1 1/2 turns out.