'08 Teryx in dire need of carburetor work

I'm looking for someone in the Charleston / Huntington area that is really good with carburetors. About two years ago I sucked oil from the crankcase vent into the intake and into the carbs while hillclimbing at or close to WOT (one of the early Teryx issues). Needless to say it ran like crap afterwards. Took it to a stealership to have fixed, $400+ later, better but not good by any means. I also added the vent fix to it to keep from happening again. The problem is that it backfires through the intake at idle or low speeds, has a miss / hesitation when you gas it from idle, and it seems as if it loads up anytime you go down hill with the engine brake holding it back. When you get back on the gas it stumbles, and then takes off. Throttle response in the mid to upper RPM's seems fine. It is also very very cold natured now. Doesn't like to take gas even when choked when cold, and if you let it idle with the choke on it will sometimes act as if one cylinder is cutting or flooding out after about a minute or so. I've had about all I can take with the issue, refuse to take it back to the same stealership since they "rebuilt" the carbs, charged me way too much and really didn't get the issue resolved. Any recommendations would be appreciated. Thanks.

I would call James  "WVHOTRODRHINO" here on the site. He can help you out a lot on this issue.

Back firing out the intake has me a little concerned. I would check a couple of other little things like valve lash, plug gap, plug wires or maybe ignition module.

the intake valves are tight from wear.dust that passed usually...adjust the valves and it will fix it....if they are wore bad it will start running out of adjustment

Thanks guys. Hopefully that will line it out and won't have to do any adjustments on the carb. Sad part of this is the stealeship told me that the valves usually don't need adjusting on them.

they are bad for it