OK so here is an update on what I have found.

I performed a leak down test on the motor. First off, I would like to say Man it is hard to get that exhaust port on the block sealed up enough to hold air!!!

Once I got the exhaust port sealed up tight, the engine was not holding any pressure. I found that I had an air leak where the air intake / reed manifold bolts to the engine. When I knelled down on the left side of the engine, I could literally feel air hitting my face, no need for soap and water to find that one. I removed the intake and reeds.

Took the reeds apart and washed them with soap and water and put them back together. Reeds all looked like they were in good shape. There were no gaps, tears, cracks or anything. I cut out and installed new gaskets and bolted it back to the motor. I set the motor to 8 PSI, and it held. It held at 8 PSI for about 5 minutes or so, and then when I went back about 15 minutes later, it was down to 3-4 PSI.

So it appears that the Engine is in good shape as far as seals, gaskets and or cracks.

I put the machine back together, and fired it up. From the start I could tell that the idle sounded much better. When I took it for a ride, it seemed to start from a stop better, but once it got to 4+ MPH, the engine was very sputtery, then once it reached 10 MPH, it sounded good. So I am guessing that my air/fuel screw mixture that I set when I had the leak, was no longer working and needed to be readjusted.

I played with the mixture screw, and got it to where it sounded pretty good. However it seems that no matter where I set the screw, from an idle, if I quickly WOT the throttle, it will give a little bit of a "hesitation". Maybe I am not supposed to WOT from idle when testing?

I also took the main jet out of the carb and it has a 190 jet. I am not sure what is stock, but the manual for the magnum said it was 200. So I set the jet needle clip 1 spot lower to make it a little richer, but it was later and I never tested it after reinstalling the jet and needle.

When I took the air/fuel mixture screw out of the carb, it had a "rounded" tip on it. Is that normal for this carb? Other machines i have had always had a sharp tip on the mixture screw. However I am not sure if a sharp tip vs. a rounded tip would make a whole lot of difference, but I thought it was worth mentioning.

 

A lot of these will still have a little bog or hesitation. You should have the rubber dampener under the carb that helps negate vibrations that the 93 models had. This helps keep a load of fuel being dumped in the engine. 200 main was stock but down here it was too rich. I dropped a lot of jets down to a 190 for the slow putter and others.Plus depending on altitude and temperature,you may be able to drop the main jet a little further especially in colder weather when engines run leaner.Main thing is to always check the plug.Should be a tan to medium brown.Actually about 2 turns out on the air screw as a base,but may help by turning in or out and experimenting. Also check different positions on the needle. Just move the clip up and down. Air screw is rounded,doesn't have the small tip that pilot(fuel screws) have on cv carbs mainly used on 4 strokes.#3130011. Leak down tests are the best for finding leaks. Glad you got it this far.

 

So it seems that my 94 sportsman 2-stroke 4x4 came with a 200 main jet stock. Mine has a 190 jet now. My elevation is 4800 ft above sea level, and the average temps from now until about late march will be about 30 degrees in the day, and 10-19 degrees at night. so if I do rejet, what jet would be a good choice?

if I am sputtering at low RPM, should I move the clip up 1 slot? I moved it down. Reassembling the filter box, when I put the black topper with the riser that hugs the gas tank, I think to myself that it seems like it might starve for air right there being placed in between the seat and tank. maybe I should just put a snorkel on it.

 

Air box and filter has to be on before you do any adjusting!! Possible you could drop to a 180-185 main and see how it does along with playing with the air screw setting and needle clip position.Just try moving the clip two places down(richer) and see how it does.If it runs worse,go the opposite way. I've jetted 400s as low as a 160 main on machines that were going to Colorado @13,000 ft or more in the summers and changed them back when they came home.Plenty of wiggle room on jetting,but again don't forget the plug color.Local dealers or Jetsrus can fix you up.https://jetsrus.com/a_jets_by_carbur..._selection.htm

 

Is there an easier way to get the spark plug out without removing the fuel tank?

 

Just go to any hardware store,Sears,etc and get a short combo off set 11/16"-13/16" boxed end wrench.The end is bent down and you can reach the plug with no problem. I have an old Cornwell Bw-2226 I've use for years on the 350/400 engines.Looks sort of like this.