250-500cc First Post

Hello everyone! Happy Thanksgiving! This is my first post on this site. Just picked up a 2009 WR300 that was sitting on the showroom floor. It's a much different bike than my 97 kdx200. So far from what I've seen this bike seems like its going to be awesome for the riding I do.
Few questions?
1.Is it really necessary to get a new spark plug after break in period like it says in the book?
2.What transmission oil does everyone normally use?
3.Does the bike squat down a bit during break in? I'm 5'8" about 180lbs. Right now I'm on my tippy toes and normally ride lots of rocky singletrack.

Congrats and welcome to CH. No you don't need to replace the plug but I would at least check it and as cheap as they are replacing it and keeping the stock one as a spare is what I did with my 125. I run the Rotella 15-40 in the white gallon jug (cheap but very good oil IMHO). Not sure on the 300 but my TXC510 and 125 both settled just a little but not much after a few rides. I think you can get a lowering link for the 300 or you can have it lowered by a suspension shop. I hear you on the tall bike deal; 5' 7" myself so lowering the 300 would be nice. Enjoy your new bike.

Congrats on the new bike! I would say no NEED to swap out a plug after break in. Not a bad idea, but not "necessary". For tranny oil I run basic 1O-40. I usually end up with Quaker State, Shell or Pennzoil, depending on what is a better deal. I change my oil in my bikes quite often, and I never have any problems with clutch fade or transmission, or anything like that. As far as squatting goes, the suspension will settle some after break in, but these are a little tall. I run BelRay H1R premix and it has been very good. It is also very easy to use. It comes in a 12.8oz bottle, so one bottle to 5 gals of gas = 50:1 exactly.
I would suggest this: put in a gasket on the cylinder side of the V force boot. There is a serial number stamped on it that can cause an air leak/lean condition that could cause an issue. If you do a search on this forum, you will find it. Super easy to remedy. I made a paper gasket for it with some gasket material from the auto store, some use a honda gasket maker. Either way, I would do that so that you don't have any issues.
Again, congrats on the new ride. I have the same bike and love it! Super reliable, super powerful and super fun!!

Have you set your sag yet? The preload is cranked up pretty good from the factory and if you set your sag about 105mm it will make it a little easier to touch.

Thank you all for the responses. The sag has been set. That helped for about 1/2 inch. LOL! Guess I will just need to put it through some trails. Hopefully it settles a bit more. One thing I notice is after a heat cycle(break in period) and short ride the bike stalls If I am in gear with the clutch pulled in when I stop. I turned the idol up a little but it still stalls. It will start right back up in nuetral. Is there a suggested adjustment or do I need to just blip the throttle a bit more at slow speeds or at stops?

Do you feel the clutch dragging? Does the bike crawl forward with the clutch pulled in and the bike in gear? My bike did that with standard oil in the trans, I switched to synthetic and it stopped lurching forward with the clutch in.

Well I took the bike for a good first trail ride today. Lots of rocks and tight singletrack with some gnarly hills. At first I was stalling alot which was very frustrating. After awhile I adjusted the clutch to where it grabs a little farther away from the handlebar so I can ride with two fingers on the clutch. Big difference. I can even start it in gear now which is great. Sucks to have to try and find neutral when your on your toes. LOL! Then I had to turn up the idol a bit. Bike is running much better now. The bike has tons of power compared to what I'm used to. Gonna just keep getting some good rides in and hopefully the suspension will soften up some more. Not bad for the first real ride. I LIKE IT!
marcmo0- you run 50:1. The dealer told me 40:1. I guess I'll need to look back into the book see what mine says. Does 50:1 make a big difference from 40:1? I was always running 40:1 on my KDX.

40:1 will work too. My manual specs out 50:1. I ran at 32:1 during my break in cycles and have been at 50:1 since. Important thing is to make sure you are jetted properly. If I am going to be doing a lot of fast, open desert, then I will sometimes run 40:1.
And if you do end up using Bel Ray, just mix it with 4gals of gas, and you get 40:1. I love it. Its really good premix, burns clean, smells good (although I have yet to smell a two stroke that I didn't love the smell of) and I haven't used my ratio rite in over a year.

Cool thanks. What about that spark plug. The last two letters are EG on mine. Whats the difference in that and the plugs ending in ES?

The ES is a standard plug, the EG is a race plug. Either one should work.