2010 Arctic Cat DVX 300 / 300 Utility ATV Service Manual, Page 67Get this manual
Problem: Engine runs poorly at high speed Condition 123456789High RPM "cut out" against RPM limiter Valve springs weak Valve timing out of adjustment Camsrocker arms worn Spark plug gap too narrow Ignition coil defective Float level too low Air cleaner element obstructed Fuel hose obstructed
123456789Shift into higher geardecrease speed Replace springs Adjust timing Replace camsarms Adjust gap Replace ignition oil Adjust float height Clean element Cleanprime hose
Problem: Exhaust smoke dirty or heavy Condition
12345678Oil (in the engine) overfilledcontaminated Piston ringscylinder worn Valve guides worn Cylinder wall scoredscuffed Valve stems worn Stem seals defective Air cleaner element obstructed Float level too high
12345678Drain excess oilreplace oil Replaceservice ringscylinder Replace guides Replaceservice cylinder Replace valves Replace seals Clean element Adjust float level