1996 Argo Conquest High Altitude main jet replacement

[ndcommander]

I recently bought a 96 Argo Conquest with the Kawasaki FD620 20 HP water cooled engine. When I bought it the guy selling it made mention that it may have had the main jet changed to operate at high altitude. Well it seemed to run ok but I thought it was odd that it rarely needed the choke for more than a minute when it was cold. Well I checked the main jet and it is a #110 I found some one one here who posted that the standard jet for 0-3000 feet elevation is the #112 I am at 900 feet elevation. If I replace the main jet will I have to adjust the other carburetor adjustments and if so does anyone know were I should start for adjusments. I noticed it has two seperate adjustment on the back side. I am not sure which is what and how far they should be out, any help would be great.

[AussieMax]

The high altitude jet kit has smaller jets than standard. If it was going to be a problem it would run too lean, so if anything you would need more choke not less. I'm not that familiar with the Kawasaki carb, but the adjustment screws are more than likely idle mixture adjustments, These only effect the mixture at idle. Changing the main jet should only make it run richer above idle.

[Rock Doctor]

I don't know what jets I have in my machines (Conquests, same engines as yours), but I have never had to choke them any longer than it takes for them to start (unless it's -20 degC outside, then I might have to choke them for a few seconds). I'm at about 1200ft here, if that helps any.

RD

[ndcommander]

That does help, I am in ND and it does get to -20 F but it doesnt take more choke than to start it. Thanks I will get the standard jet and go from there, hope it gives it a litle more juice.

[JohnF]

A quick and easy test is to let it run for awhile to get warmed up and then (no load, in neutral) hold wide open throttle. If it is too lean it will surge and sputter and die. It's not a perfect test because there are many reasons for it to be lean or surge - but it is how I check. (I am at all kinds of different elevations.) As for the other adjustments: The port side screw is a drain. You can adjust the idle air mixture (the other protruding screw in the back - may have a plastic cap) and the idle rpm (throttle stop screw on starboard side of carb). The truth is that for optimum performance (uh, in idle...) you should adjust these whenever the air density changes - so temp./pressure changes. To adjust air mixture turn your idle up a bit high - then turn the screw in until you can hear the rpm drop then out until it drops then set it just a smidge rich of center. Idle RPM is low enough that you can shift gears but high enough that the alternator (I have one ) works.