Hard to start when new

Was everyone's YZ250F harder to start at first? I have now owned 2 and they were pigs for about the first 3 hours of operation,more on the 2002. Just a question. :)

i would imagine that this is no fault

just a fact that its new and the cylinder is tight and hasnt had a chance to bed in yet.

if it goes away then its nothing to worry about


swap the plug after 5 hours.

yeah mine was hard to start. i think it was a combination of a few things.

1. i needed to learn teh proper way to kick it. Keep slowly crankin the bike until it gets hard to push, then let the crank all the way up and give it a good kick. this definately helps for me.

Also, my idle was set too low. I needed to raise it significantly. that made is start better. Recently i put a bigger pilot jet in and that also helped a lot, especially in the cold.

When I took delivery of my '04 YZ250F in June, I kicked and kicked for a good twenty minutes until she fired up. Its normal. I was even following the start-up procedure from ThumperFaq.com.

I have two, the first one was very hard to start - 20 minutes kicking! I was ready to take it back! Once it started it has been fine since. It had never been started even at the dealership I think. The second one had been started once and my daughter has been able to start it without difficulty. So I think it just that initial "firing" up. Oddly enough my 03 never did this.

The blue wire mod and power now made my bike start much easier. The Blue wire only helped on cold starting though.

Are you jetted correctly? Mine was hard to start when cold till I backed out the fuel screw 1/4 turn.

My 05 WR (same engine as the YZ) was a bear to start when it was brand new. I was convinced I had seized the piston the thing was so hard to kick. Still not sure why. Has never done it again since then.

Same here with both bikes. Hard to start on break in. I have since learned that I don't need to kick "hard". I get better results with a steady smooth kick. Sometimes my 450 will fire while I'm trying to find TDC. :)

It's not the power of your kick, but the speed of it. you have to spin the motor fast to let the generator build up enough juice to power the ignition.

The 03 - 05's have no starting procedure. There is no need to roll them to top dead center. You just need to kick it as fast as you can.

The new engine carbon fouls the plug quite easily in the first few hours. Theres a lot of blowby until the rings seat. Changing the plug out will help immensly, and opening the gap up to 0.040 will also do it some good too.

Ahh, this might explain mine wanting to be hard to start, I have about four hours on my bike and the plug is probably starting to get all gunked up.

One other thing I heard was that if the bike sits for awhile, the evaporating gas leaves behind a residue that makes it hard to start. Any validity to that? Mine sat a few weeks in between firing it up since I am still looking for places to ride, but now I try to start it for a few minutes at least on every weekend just in case.

The 03 - 05's have no starting procedure. There is no need to roll them to top dead center. You just need to kick it as fast as you can.

It's a habit coming from my WR. I never did put an 03 cam in it. I have kicked over my YZ without finding tdc but it seems to start more reliably if I find some resistance first. 1 kick instead of 3.

The bike starts good now, thanks. I just wanted to see if it was isolated. :)

I always lean the 250f's and 450f's over far enough to get fuel to run out of the float bowl. Normally start on the first kick after that.

The 03 - 05's have no starting procedure. There is no need to roll them to top dead center. You just need to kick it as fast as you can.


Maybe, but my F always starts better and easier when i bring it to TDC...espcially when im first starting it. its an 04 :)

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