HI I HAVE A 2001 400 4X4 AC IT HAS ABOUT 3000 MILES ON IT I NOTICE NOW WHEN I TAKE THE OLI CAP OFF WHILE RUNNING OIL AND LOT OF AIR BLOWS OUT LIKE IT HAS COMPRRSION THERE AND THERE IS NO SUCTION ON THE AIR CLEANER OPENING WHEN BEFORE IT SUCKED A LOT IS THUIS NORMAL.
AND IS THERE ANY CHEAP WAY TO GET THIS THING TO MOVE FASTER
THANKS

 

It's normal. You aren't suppose to remove the oil cap while the motor is running, only when off. You could have a plugged crankcase breather hose. Remove it and see if it is clear. FYI, drop the all caps. It's the same as yelling on the net. Speed always cost money and more speed always costs lots more money.

 

I have had the crankcase vent tube get plugged with a chunk of ice. This caused the hose to blow off the crankcase and it did the same thing. So definitely check the crank case vent tube. It connects to a point on the back of the engine and then connecects to the air intake. Easiest to see it is by looking at the back of the engine where your right leg would be if you were sitting on the machine. You may need to remove the seat for some light.

Also don't run machine without the oil cap off. It makes a mess and wastes your oil, and oil is getting expensive!

Your 400 should hit 45 to 50mph. If you feel the need to go faster, then look into a sport bike. These machines are a utility sport bike. 45 mph is plenty fast enough when you are carrying 400-600 pounds (or more) of gear!

With 3000 miles you might check your valve adjustment though. inproperly adjusted valves can cause poor performance.

SJ