2003 Sportmans 600 cold start upgrade?

[brassmagnet]

I recently purchased a 2003 Sportsman 600 and have been reading up on what kinds of problems etc are associated with them. At one point I remember reading something about a cold start upgrade that was offered for the early 600's and I was wondering if anyone new anything about it?

I currently have the carb apart for cleaning purposes and I was wondering if the cold start upgrade may be something simple like going the next size up on the jet. The stock jet size (and what was in it the carb) is a 155. The next size up is a 157.5.

I have also read that the stock jetting on the 600's was pretty lean - based on that I was wondering if it would be a good idea to up-size the jet while everything is apart. From everything that I have read it seems one is better off having things run a little rich than having it to lean. If anyone has any info on what the cold start upgrade may be and/or if they have ended up re-jetting their 600's etc. please chime in. Thanks in advance!

[Bruce!]

Welcome to the board!

[4getful2]

The main jet is in use at higher rpms,'bout 3/4 throttle. You may be needing a larger pilot jet,if you are having lower rpm problems

[Russ C]

yes go up one size on main jet and set fuel screw at 2.5 turns out, where was the e-clip on main jet needle at?,

[brassmagnet]

Thanks for the feedback... Yes there is an e-clip on the needle, but unfortunately I don't remember which position from the top it was in (not at home right now). I ordered another standard jet and the next size higher - still waiting for replacement carb parts to arrive.

The reason I opened the carb to begin with was that I noticed a slight gas smell from the oil and the air cleaner had a strong gas smell as well. I figured that the float needle/assembly might be worn. As soon as i pulled the fuel line to the carb I also realized that the fuel shut off was no longer working and still allowed a fair amount of fuel to continue flowing even when it was in the off position (pretty sure that this didn't help things).

The main needle looked like it was in good shape - not shiny or discolored anywhere. The float needle was indeed worn on the outside ridges and the pilot needle looked a little worn as well. Needless to say these are going to be replaced.

Seeing that I'm in no immediate need to have the atv running for ice fishing (due to the wonderful weather in WI that can't decide whether it should be warm or cold) I might just play around a little bit with the carb. Originally I had come across a few posts that indicated Polaris had up-sized the jet on the 600's depending on when it was built. I have no actual proof that Polaris did this so I'm just trying to get a feel for what others may have done/experienced regarding this...

[Russ C]

e-clip should have been in middle position, try it wityh larger jet, if its still hard starting lower clip one notch and try it, usually one size larger jet will cure it, Ive done this to2 other 600's and it made them start and run much better

[brassmagnet]

Thanks for the info Russ! Once my parts come in I'll give it a try!