Bike won't start!!!

I have an 04 450 all stock. A week at the most past since I last rode the thing and it usally starts on the second or thrid kick. Last night it took me forever to get it started to I could check the oil level, but it did start and I ran it for about 90 - 120 seconds or so.

Today on the other hand, a perfect riding day, I got home from work really looking forward to a great afternoon of riding. I mounted the bike and after about 15 kicks I was out of breath. I tried putting it in 5th and rolling it as fast as I could just to hear it was sparking. It sounded like it wanted to start but I couldn't push it fast enough to do so that way.

So I lay a good 25 or more kicks and it started and ran about 3 seconds and back firing to a stop. About 20 more kick only resulted in a very very pissed off yz450f owner! :devil:

What could be the f..ing problem? I'm on my last nerve with this bike... if it keeps up I'll be purchasing a CRF450 or a .......dare I say.... a 660 raptor w / elctric start!

Please calm me down. :devil::D:cry::cry::cry::cry::cry:

How long has the bike been sitting? You may have gummed up the carb if it sat with fuel in it for a few months. :cry:

Try replacing the spark plug even if it still looks good.

Is it colder since it ran? Warmer? Have you done any maintenance during the week that could affect starting? Did it run differently last week? Is the gas still good?

????? Be at ease. You will figure it out.

I agree with the spark plug swap. Also, how clean is your filter?

Swapping to a CRF won't change what's going on right now. I had to start a guy's CRF once because he couldn't get it started. Turned out he had a dirty filter. Makes a big difference on these bikes.

Its only been about a week since last run...I actully started it last night. The temp outside is a little warmer, I cleaned the air filter 2 weeks ago ( only about 2hrs on it since ) I know the gas is good, maybe 2 weeks old at most.

I did pressure wash it before putting it up last. but like I said it was hard to start last night but it did start up a run fine. Today not luck...just a good workout for my right leg

I know it sounds crazy but take a look at your pilot screw.Everyone told me I was crazy but mine fell out not long ago.

FWIW - I just picked up a MINT '02 YZ 426 & it usually starts 2nd or 3rd kick cold - 1st kick warm, every time. Was running like this for a couple weeks & then one day after a wash & then sitting in the garage for a couple days it wouldn't start.

I probably kicked at it for about 20 minutes - nothing.

Pulled the hot-start button & it fired up 1st kick.

The bike was dead cold, haddn't been run in several days, was barely sputtering every 10th kick - nothing. Then the hot-start button made it start.

Mystery to me, but it's been working fine ever since.

You know ive noticed some guys will tell you they give there throtle a blip or two before a cold start and some dont. I for one DONT EVER touch the throtle before ANY start up sequence EVER. I lean my bike over till i get fuel pissing out the overflow tube, pull the choke and 1 or 2 kicks she responds with a roar. :cry::cry::cry:

I had a similiar problem with my YZ450--I know about kicking too much I wore a hole in the tread of my sneaker! Anyway went to the dealer replaced the plug with a brand new one--choke on, no hot start,no twists on throttle and gave it one kick----it started on the first kick!!! The YZF's seem to be much more "cold natured" that the WRF's. The choke has to stay on for a while; unlike my WRF which I turn the choke off just a few seconds after the motor starts.

Make sure you have the gas turned on. I have been out in the yard cussing a blue streak :cry: to find out the gas was turned off (I'm sure I'm not the only one :cry: ). If it is on then I would change the spark plug.

Yeah, I think it is spark plug....my 426 did't start in 15 kicks stone cold, put in a fresh plug and 1 kick and its fired.....Amazed me the first time I did it! :cry:

Okay... I will try the spark plug. Is it easy to change out. I have changed plenty of plugs in my day but never done one on this bike. This bike makes me nervous to work on it... nothing like my 79 Jeep or the Brigg&Stratton motors. Every thing else I own is diesel. The plug on this bike doesn't look like a walk in the park to change out. Any thing I need to know?

The only trick with changing plugs is that the top frame tube goes right over top of the plug (after you have the shrouds and tank off). This can make it hard to loosen/tighten the plug and get it in and out. So make sure you have the proper length socket extension and a spark plug socket that will grip your plug (if not you can use some tape on the inside of the socket to make the plug fit a little snug in it).

No, not really. I Just pop the seat/tank/rad shrouds, pull the rubber cap. Then I just blow compressed air in the weep hole in the right side of the motor, to make sure there is no water/dirt in there. Next, take plug out and reverse the process...... Hope this helps, Pete :cry:

P.S. like assgasorgrass said, use something to pull the plug up and out. I use a rubber tube after the plug is completely unthreaded. But thats just my way..... :cry:

Sh!t... I got to pull the tank!!!!!!!! Why can't things be easy as my good ole jeep?

Thanks for the advise guys. I'll change it tomorrow. I will post if it works or not.

To pull the plug out just use a socket with the rubber insert. Those sockets will hold on to the plug nice and tight (a real spark plug socket).

FWIW - I just picked up a MINT '02 YZ 426 & it usually starts 2nd or 3rd kick cold - 1st kick warm, every time. Was running like this for a couple weeks & then one day after a wash & then sitting in the garage for a couple days it wouldn't start.

I probably kicked at it for about 20 minutes - nothing.

Pulled the hot-start button & it fired up 1st kick.

The bike was dead cold, haddn't been run in several days, was barely sputtering every 10th kick - nothing. Then the hot-start button made it start.

Mystery to me, but it's been working fine ever since.

After my 400 sat for a couple of weeks and it was cold outside I had to kick it a bunch of time and then did the old hotstart and it fired up on the first kick. I am not shure of why it works but it does. I hope that you get it figured out.

I have to pull the hot start on my '04 450 when it's cold as well..not every time but if it won't start after one or two kicks I pull the hot start and she fires right up.

I have to pull the hot start on my '04 450 when it's cold as well..not every time but if it won't start after one or two kicks I pull the hot start and she fires right up.

That's exactly it. Perfect description. "...not every time, but if it won't start after one or two kicks I pull the hot start and she fires right up."

That's exactly the way mine works. Seems like it works that way hot or cold.

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