250-500cc 2010 WR 300 Jetting

Can anyone give me an idea on what jetting changes I should do at all on my new 2010 WR300, everthing is factory specs, untouched on carb. I plan on leaving the stock Mikuni on and maybe change down the road to the keihn pwk 38 if I cannot dial it in. The dealer told me he can usally get them running crisp without having to change carbs. I plan on leaving the bike stock, no porting or cylinder head modifications. The bike has more than enough power for me, I am just a trail rider and may do an occasional hare scramble. I live in N.E. OH and do most of my riding in N.W. PA and Hatfield McCoy Trails in WV.
Should I change the main and pilot jet, change needle position, and how many turns on air screw ?
Or just leave alone, it seems to start by 3rd kick and idle fine, have not had on the trails yet though....
Also a jetting kit came with bike, are they really rich from the factory and since it is new with a couple break in hours on it should I continue to run my fuel mixture at 32 to 1 Any input would be helpful.

what part of NE Ohio?

Youngstown

I grew up outside Alliance. Still have alot of riding buddies out that way.

Check the two stroke jetting data base. There is lots of useful stuff and info. I have just swapped TMX for an airstryker and the change is well worth while. The TMX was difficult to get how I wanted it and always felt like there should be more power available especially at the mid range and top end. The PWK appears to make more smooth power across the range with the bike runing much crisper and no spooge anywhere.

By the way I use motul 800 at 40:1 for the first couple of tanks and then 50:1 ever since. I don't know how many hours I have put on it, but about 1000miles and the piston, rings and cylinder look great.

Looked at thread and could not find anyone with a WR 300 that left stock carb (Mikuni) for comparison.

I just got the Mikuni running crisp and clean on my 09 WR250 and it really wasn't that tough. It responded to every change I made just like it should. I don't see what all the negative Mikuni talk is all about.

I dont think the Mikuni is necessarily bad, its is just that the PWK seams to release more power easily. So far as cost was concerned by the time I bought several Mikuni jets, maybe a throttle slide and some needles it was the same as a new Keihin with a JD kit and several spare jets. I guess the best thing would be to have a ride on 250/300 with the PWK and do some back to back testing.

From a dynorun when the Mikuni was compared with the Keihin the Keihin gave 3,5 more hp at 300 rpm, and 5 horsepower at 3500rpm. That says it all, and when it comes to jetting the Keihin is less sensitive to weatherchanges. It´s also very easy to rejet with it´s screw-on top and just twist the carb in the boot. You change needle in 2 minutes. I have tried both and laborated a lot with needles and jets. The best setup with the Mikuni for me was to use a needle named 6DEY15-74 and 460-480 main during wintertime.
I think this is a stock needle for Yamaha YZ 250 -00, but i´m not sure.

Johnny.