4000 RPM idle on 600 xlt Polaris

Check the carb boot adapters and the crank seals for leaks. Any leaks can cause a lean condition and can result in engine damage. You can spray carb cleaner or engine starter on the PTO seal and on the carb boots while the engine is idling; if the idle changes, you have an air leak.

If no air leak, try turning the air screws IN 1/8 of a turn. Turning the screws IN will result in a richer idle air/fuel mix. You can keep turning in 1/8 of a turn until the screws bottom out; if they bottom out, go back and make sure the air and fuel passages to the pilot jet are spotlessly clean. You may have to run a small wire or fishing line through the carb to dislodge any debris or varnish. Also, "floss" the pilot jets to make sure the varnish has not caused the jet to become smaller. If there's a doubt, replace the pilot jets, they are not too expensive.

I Ave a 1999 Polaris Xlt 600 spécial and the plate in the carb broke do some one know we’re I can find it

is this the reason you went thru the carbs, or is the result of your cleaning ,,if the latter ,, try again

Welcome
Start a new thread with a pic of what broke?

If you’re still looking for info about the high idle, I found that after cleaning m carbs this year that last years slide height was way too high as chunks of crap may have been blocking fuel. I chased boots, idle and air screws, filters, and it occurred to me to check the height of slides on my 96 xlt. I lowered them to closer to 1/4” from closed and it fixed that high idle.