Polaris ATV forum - all models - Polaris 2004 sportsman 400 - adjusting valves

how to adjust valves on a 2004 polaris sportsman 400.

how to adjust valves on a 2004 polaris sportsman 400.

to adjust the valves, you will need to remove a few parts off the atv so you can access the valve cover.
after you have gained access to the valve cover by removing the fuel tank, maybe the front fender, and any other parts in the way, you need to remove the very top cover of the engine - valve cover.
At this point, before you adjust the valves, you need to be sure the engine is timed at the right spot so you get an Acurate lash measurement.
When the piston is at the top of its travel, aka Top Dead Center, you need to be sure it is TDC compression, and not TDC overlap.
The best way to tell is to watch the camshaft. When the engine is on the right TDC the lobes on the camshaft will point directly down.
You will know the engine is TDC because there will be lines on the camshaft sprocket that are level with the cylinder head.
On the right and left side of the cam sprocket, you will see small lines that go from side to side. When the cam lobes are pointing down, and the lines on the sprocket are level with the cylinder head, then you can measure the valve lash.
The system is a "screw and locknut" setup, which is a very well used system. If the clearance is not correct, loosen the locknut, and turn the screw untill the right clearance is achieved.
Then retighten the locknut. (use lock tite blue to avoid the nut falling off), make sure you use a new gasket, or clean it and use a gasket sealant.