Its been my experiance that alot of socalled "Polaris techs" are nothing more then average doityourselfers.
Evedently Polaris tech training only requires the most basic intellegance. I am soon to be on my way to a 3rd (Third) dealership to try and get my hard shifting issue resolved.

 

JjEjFjf, your hard shifting could be caused by clutch misalignment. Has any of those dealers checked that?
Also robne68 is your engine a 400 or a 250? They have different types of check valves.

 

Charlie, it is a 250cc.

 

The first dealer claims to have taken out a shim.That helped very little.
The second dealer said that that the alignment was within specs.
The odd thing is that on occasion it will shift as smooth as butter.

 

JjEjFjf, the clutch alignment has to be almost perfect especially on 06 models because the primary clutch has a lower drive ratio at engagement than previous ebs models. Alignment needs to be checked with the tool at the top and bottom of the two clutches. It is not uncommon to add a shim to the top engine mount and move the front lower in addition to adding or removing shims from behind the secondary. It can be a real pain in the ***.
Now for the oil pump problem, the main subject of this thread, Robne68 I assume you have a Trailblazer and it looks like that check valve is mounted on the pump with banjo fittings. That is much easier to deal with than the old style that is pressed in to the cylinder. It is possible I suppose that oil could leak directly from the pump into the crankcase from where it is driven off of the crankshaft if that seal was defective but that would fill your crankcase not your carb.
Charlie