Oil Weight

[millertime1234]

I changed the oil in my 2003 400ex a while ago and used the honda 10-30 oil. Ever since I changed it it seems like it takes 10 times longer to start and warm up. Before I changed it it just fired right up and idled like a dream. Now I have to keep my thumb on the throtle. Is the weight to thick should I use 5-30 (I live in illinois and plan to ride it all winter).

[quad]

The weight of your oil is not the problem.I use 10/40 in my quads.I never have a problem.I know several people that run 20/50 in the summer,and 10/40 in the winter due to the colder temps.I wouldnt use the 5/30 if I was you.It is a lighter oil,and will break down quicker i believe.As far as the idle question,it is beginning to get colder out.With the colder temps,starting/idling becomes a bit more of a process.But you cant just think changing your oil is all the maintanence you need to do to your quad to keep it running good.You also need to clean and oil your air filter also.A clogged air filter will give symptoms as you described;thus meaning a loss in performance at start up and when its warm.
It sounds that your problem has came gradually.Thats why I say it may be your air filter,because they dont clog all at once;its a gradual process.I hope this helps ya.Good luck!!

[millertime1234]

Thanks a bunch I appreciate it. I just don't think its the air filter because I just bought a brand new K&N but I could try giving it a recharge I have been to the track a few times while it was real dustey but thanks for the reply I greatley appreicaite it.

[quad]

Not a problem.I cant guarantee thats what your problem is,but its worth a shot.Ya might even want to clean your carb too.Can only do good for it,right?LOL:)