yfz 450 carb trouble -- high idle -- PLEASE HELP !!

I just purchased an '04 yamaha yfz 450 a few weeks ago that has some carb trouble. The guy I got it from said the carb just needed a good cleaning. Come to find out when I got it home and pulled the carb out, it was missing a screw on the quick shot pump and the air/fuel mixture screw wasn't even there. It did not have the stock main jet and the stock needle. It had a 175 main jet with the clip on the last slot on the needle.

Right now it has the airbox lid off with a UNI air filter. It had the stock pipe but I bought a DR. D pipe ( slip on ) on ebay and installed it. The pipe is missing the end cap and the quiet core on it so its wide open. I took the bike and carb to a friend that has two '08 yfz 450's that has worked on these carbs. We went to the DR. D website and its calling for a 172 main and the clip on #6 slot but it doesn't say for what elevation. I live in arizona which is about 3000 to 3500 elevation. My buddy had his stock air/fuel mixture screw but with no spring.

I went to a couple motorcycle shops looking for a 172 main jet and a air/fuel mixture screw spring. They didn't have anything in stock but had a 170 main jet and one of the service dept had a spring but couldn't guarantee that is was for the yfz450. My buddy put the 170 main jet in, cleaned the carb really good and put the air/fuel mixture screw in with spring. The spring seemed to be just a tad too small so he pulled the ends on the spring to expand it just alittle to make it work. It did go in and he screwed it all the way in and came out 2 1/2 to 3 turns on it. He also put the clip on # 3 or 4 instead of what the website was calling for.

He put the carb back in and the bike came alive. But it has a really high idle now and he is stumped as well as I am. I rode the bike and it seemed to run ok but it still has alittle bog and it backfires alittle.
ANY SUGGESTIONS ON WHY IT IS IDLING HIGH NOW AND HOW DO I TUNE IT IN TO MAKE IT RUN AWESOME ??? AND DO I NEED TO RUN A 172 MAIN JET AND GET THE RIGHT SPRING??

I havent gotten to ride my baby yet and had to miss the first day back at the dunes this weekend. PLEASE HELP ME!!  

Sounds simple, but is the thumbscrew still in it? If so, run it out a turn or 2. If not, check your idle screw.  

Thanks soo much raptor660 for the response. Well the thumbscrew is in it and has the spring ( which might not be the stock yfz450 ) but my buddy put one in and had to pull the ends out alittle to make the spring work. He turned it all the way in and turned it back out 2 1/2 turns. He put the carb back in and it ran way better and rode it around for alittle while but it had a high idle. We adjusted the idle way down but still has the high idle.
Im thinking it could either be the carb not lined exactly up with the boots because on both sides they have two notches the carb lines up with. It could either be that or there is a leak somewhere. I heard you can take carb cleaner and spray it around the carb and if it dies down, then there is a leak, Or it could maybe be my pilot jet being the wrong kind,
I havent got a chance to mess with it but this week some time I will check all situations. I have a repair maunual and will see if that helps me as well. But I will do what ya said and see if that helps as well.
When I bought the bike it barely ran and it ran like *** We took the carb out, it was missing the fuel/air mixture screw and spring, it also had a screw missing on the accelerator pump . We didnt have the exact kind but put a temp screw in. It still could be that wrong scew not being tight or it could maybe be the gaskets being bad since this carb has been apart quite a few times.
But thanks for the info and will check on those few things. I will let ya know what happens k? Thanks raptor660 for the response. I have been waiting for a month on someone to help me out. WIll KEEP YA POSTED K?  

Good luck. By the way, check the travel of the throttle cable cam on your carb. It's possible that something may be holding it at a ceartain point even after the throttle is released, and make sure the throttle cable is the proper one. One way to tell is to take the t cable off the carb side and see if it(the throttle cable cam) goes further back into the relaxed position. If so, wrong or improperly adjusted cable. Hope this helps and it's something simple. I never had forums like this when I started in this sport.