96 Venom 225 recirculation valve question

[Camelot]

I have a 96 Venom 225 that runs perfectly at 2500 rpm and above but coughs and sneezes at times when idling. I have a feeling it may be recirc valves but I'm not really sure how to check. Initially I thought I would change all 6 but they are a little pricey and I dont want to change just for nothing. Any ideas?
Thanks

[ChampioNman]

You will need to remove them to test. Place them in a plastic container and add some Isoprophyl alcohol, clean the screens on the end of them. To test, you'll need a syringe and a small hose attach the hose to the nipple of the valve and see if you can push the alcohol thru the fitting if you can it is defective..the test process is in Chapter two of your service manual.

[Camelot]

This is where I get a little confused. There is a check valve that can be removed without taking the intake manifold off i believe. Then there is a check valve assembly that appears to be part of the intake manifold. Am I checking (no pun intended) the threaded nipple part or the part with the little screen in the intake manifold?
Thanks

[ChampioNman]

The actual recirc valves screw into the side of the front half of the crank case, the valves you are referring to are pressed into the front side of the crank case and are simply screens, to remove those the carbs/throttle bodies need to be removed along with the recirc valves and you use a scribe to push the screen out. Sorry to confuse you, my coffee hadn't kicked in yet and meant to say front half of the crank case and not the intake manifold. Here is the recic valve.