Just went out and purchased a new spark plug, still lacks power.

Another symptom, in neutral i can rev her, and it takes a good 20 seconds and then she starts to climb to a high rev, veeerrry slowly though. So she is capable of a high rev, you just have to wait a good 20-30 seconds and have her in neutral.

Oh and i cleaned the old spark plug, put it in, rev'd her a bit, then took the spark plug out and it was covered in carbon, it was black, thin layer of black all over the spark plug

(Edit) After looking at some charts, the spark plug is "Carbon Fouled", she has a layer of black dust around the end. So this screams "Carb" to me, which was my initial thought..

Maybe i just need a new air filter, maybe shes getting far too much air.

/shrug, even played with the choke cable to make sure it wasn't the choke that was "Somewhat" on..

 

Heads up, I played with my Pilot screw, twisted it alll the way in then brought her out 1 1/2 turns like the "Claymers" manual says.

Then i brought the clip up near the top of the Main jet needle, for a "leaner" mixture, and let me tell you i am seeing one hell of a difference, she somewhat screams down the road now. But she still doesn't reach top speed, so i guess i'd have to screw the pilot screw in more? Or bring that needle clip up another notch for even leaner mixture?

 

set the screw at 2.5 turns out, put clip on needle in the middle notch, let us know if it works.

 

Did so, she still runs at about 3/4 throttle, but before this carb issue, topping her off with gas would do the trick and give her all throttle back.. why would it do this? i'm at less then half a tank now, i bet if i filled her she would top off in speed again.

 

try putting your gas valve in reserve and see what happens maybe your pickup tube is restricted in the on position

 

pickup tube? She runs the same both in res, and in Norm. Made sure the fuel pump was working, seems too, disconnected the fuel line from the carb while she was operating and sure enough the fuel was dribbling out, as oppose to not coming out at all when she was off.

Maybe the fuel pump pressure isn't high enough? Hence why when the gas level is at max, the fuel pressure increases dramatically due to the gas level being much higher then the carbs float level.. but once it drops it depends on the fuel pump, which lacks pressure? then again it shouldn't be sucking that much gas.. a dribble should do it i would assume.. no clue

 

Loosen the gas cap, sounds like the vent maybe plugged, also check that both breather tubes are connected to the front of airbox, one on right side of intake boot and one on the left.

 

My 2004 700 Sportsman did a simular thing. Turned out to be fuel pump.