450 starting

Hey everyone, the names Zach, been skimming over the forums, and thought id join in. I ride a 2004 yz450 and live in San Diego, Cal.:devil:

anyways, i changed the oil in the 2004 yz450f i recently took ownership of, and its hard to start now. i used the recommended oil in the manual, put a little more then a full quart in, and it starts, but it takes a lot more kicks than before i changed the oil. it starts, it runs, not as good as before, but sometimes dies when given throttle, after warming it up for a minute or so. Its probably a minor thing, but i cant figure it out. i tried to get the plug out to check it, but my spark plug wrench doesn't reach long enough. i dont give it any gas when starting. im just wondering if anyone knows how i can fix this to get it back to how it started before(1-2 kicks), has anyone had this problem after changing oil? i didnt take out the plug and kick it a few times like some people say to, so maybe thats it. im knew to the fourstroke stuff, let alone motorcycles in general(been riding 4 years, know general two stroke maintenance) so any advice is greatly appreciated.:thumbsup:

thanks much

My own '03 450 has never started well unless the throttle was cracked slightly open when cold starting (choke on, 2-3 twists, push through once, crack the throttle and kick. normally takes no more than two, usually one)

Get a plug wrench that works (Motion Pro makes a handy one). Your problem, if not relieved by a change in technique, could be the plug. Try a new one. Also, be sure your idle fuel screw is trimmed right.

thanks for the imput. can you tell me what you mean by the idle fuel screw being "trimmed right"?

This info is for a 250F, but the procedure is exactly the same. You will very soon find out why people like the extended idle fuel screws.


awesome. I think my problem was messing around with the idle adjustment knob too much when the engine wasn't warmed up, and now its idle isn't right. Ill give this fuel screw a try, and see how it turns out, thanks again.

Another reason your bike may be hard to start, your valves may be due for an adjustment?

the guy i bought it from had them adjusted when i bought it, which was a couple months ago, and before i changed the oil, it started in 1 kick most of the time, so i dont think its the valves, but you may be right.

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