wont start!?

[trx400Rider]

I have a 2006 450ER that will not start. it has a ehs air lid, hmf slip on, and I have it jetted with a genuine keihin 185 main and 50 pilot. Havent touched the air/fuel screw or needle position. its still in factory spec.
Its getting great spark, and seems to be getting gas by the smell of it from cranking it over and over. It seems like it wants to fire up but doesnt . Ive installed the ehs lid and rejetted it about 10 hours of run time and now all of a sudden its giving me hell to start it. do you guys think Im running to rich? or? I put a new NGK plug in it also.
But it started doing this after I changed the oil. i let the oil drain out over night then filled it back up in the morning and it wouldnt start. finally after messing with the idle adjustment and hooking up a battery booster it fired up.
There is probably 60 hours top on the entire engine. if that matters any lol.

Hope someone can help me!
Thanks!

[450rdr424]

are the valves in spec? that would be the first place i would look

[trx400Rider]

I haven't had the valves adjusted yet. I wa suposed to take it to the dealer last week but didn't. You think they can be that far out of spec with just 60 some hours? I don't beat this quad. Change oil every 5 hrs and clean air filter before every use . But I guess these engines aren't nothing like a 400ex lol
it still won't start easy though. When it runs it sounds like it always has . think my jetting is wrong?

[450rdr424]

after you have ran it a while take your plug out and see what color it is, i shoot for a milk chocolate brown with mine. that is the best way to tell on your jetting but if you get it running and warmed up does it start alright after that? i ran a gncc race quad ran great, the next day i went to start it to put it in the trailer and wouldnt start, ended up being the valves were tight. i would say even with 60 hrs on it they can tighten up. would start there but check your plug also, white is too lean, black it too rich, chocolate milk brown is good.

[trx400Rider]

After it starts up and runs for a few seconds and I shut it off, It starts right up without a problem. I just don't understand why its so hard starting. When I crank it, it sounds like it wants yo fire up but doesn't.
my spark plug is a mix between brown /black and then grey. What's that mean? Thanks!!!

[450rdr424]

spark plug doesnt seem that far off, i am betting it is the valves. Usually after it warms up it starts better even if the valves are tight. i would get the valves checked and re-shimmed