Carbed Polaris products - air mix screw setting

[butcher bergs]

I've owned my '02 Sportsman 700 for a few years now and it developed a hard starting condition when the engine was cold. The condition slowly developed over the last year and got to the point where I'd need a jumper pack and 20 minutes of time in order to get it going and since starting fluid is for "other" people, I was forced to find the source of my machine's issue as the time required to cold start proved to be unacceptable.
I realize the charging system on this model leaves something to be desired but this thing should fire up provided the battery is fully charged...and it did when the plugs were new.

All of the intake rubber was in good shape so I looked into the carburation. After going thru the carb to ensure everything was clean and working properly, I went out on a limb and decided to address the air mix screw. As luck would have it, Polaris (or Mikuni) pressed a brass slug over the air mix screw. Being familiar with jet kits and the need to drill the slugs out, I chose to start drilling.

Once the slug was removed I grabbed a precision flat head screw driver and wanted to see what the factory setting was so I started turning the screw in and found out it has, since 2002, been set at 0 turns out. Zero? Yes, zero.

Well gee whiz! I think I found the source of my problem.

Went with 1.5 turns out since the machine is completely stock and all seems good.

I am puzzled, though....before this adjustment was made there was a stutter in the driveline during partial throttle (like uneven fueling delivery) that was eliminated however I'm not understanding why this is.

Regardless, if you are reading this and have a carbureted Polaris product that is hard to start when cold, consider looking into the air mix screw setting provided you are certain everything else checks out.

Zero turns.....

[Kurlon]

The idle mix impacts the entire throttle range, so it very well could be the cure for that light throttle stutter.

[Paul_E_D]

Times have surely changed. I read this title as car bed several times before I understood. WTF.

[butcher bergs]

The idle mix impacts the entire throttle range, so it very well could be the cure for that light throttle stutter.

Still, I am somewhat mystified by the result since the engine did not sound like it was unhappy. Up to this point I've always thought the drive belt had some wear spots. Turns out not so.


Paul - I will spell it so it's easier to understand..... Carb_E_D

[Paul_E_D]

Bwaha!!