Help! I'm about ready to sell it!!

At the risk of sounding like a complete spaz, I really need help starting my YZ426. I have had it for nearly a week now and have only been able to start it twice. As far as I can tell I am following the cold starting drill as it is carved in stone, but I MUST be doing something wrong. Any suggestions would be greatly appreciated.

Anxiously awaiting responses, med56


(just kidding :) )

You may just be flooding the bike as you try different ways to get it lit (choke on/off, idle up/down, throttle blip to prime cyl. yes/no).

If it doesn’t start (or threaten to) in five kicks or so stop and rest (whew!) and kick through rapidly ten times (choke off, no throttle blips) with the compression release pulled to clear things up. That way you will be starting fresh the next time you kick it over.

You may want to try a new plug and fresh gas if you haven’t already.

Another thing I’ll throw out there, assuming you’re the second owner, is idle mixture. Stock should be 1.75 turns out on what is alternately called the “fuel screw,” “idle mix screw,” and “pilot screw” (but don’t call it an air screw!). This is hidden in a recess on the bottom of the float bowl towards the front of the bike and requires a short, narrow slot blade to turn it. The screw sits on an axis that is roughly vertical (it leans front to back about 15 degrees if you’re gonna nit…).

Does the bike start easily once its warmed up (don’t tell me you haven’t stalled it yet)??


Thanks man! I did actually stall it the first time I got it started. At that point I pulled out the hot start button pulled in the compression release and purged it by kicking it over a dozen or so times. I then went back to the drill and it lit right up. Those are the only two occasions I've been lucky enough to get it running.

What do ya think?

You are defianltely not the first to ask this question, in fact I think we all did when our's was new. The methods above are good but you need to trial and error your particualr bike to find what works best, mine started a little differently than most others I've been around but now starting is easy. Was a beast when it was new. Also it starts much better after 10-15 hours anyway. I drug mine out of the shop this evening after it being un-started for 3 weeks and it fired 2nd kick. It's cold here too so keep kicking...


When I bought my 00' YZ it took me about 4 good rides before the motor started to loosen up enough to kickstart easily,

HOWEVER it took at least 10 kicks on average (when warm) to start UNTIL I fixed my jetting. It was for the most part not ridable until I did this. 2 up on the pilot and 2 up on main made it a new (and likeable) bike.

Don't give up... My 2000 426 was my first MX bike and at first I had difficulty starting, but once I got the technique it starts first kick almost every time. I follow the technique in the manual. At first it seemed like I was following it exactly but still had trouble but now don't. The key points were: 1) Don't touch the throttle. Since you naturally want to, don't even put your hand on it. Put your right hand on the crossbar to make sure you don't even accidentally touch the throttle. 2) After you depress the kickstarter to top dead center, release it and pull in the decompression lever, only depress the kick starter ONE INCH!!! Then release it, let go of lever and give it a solid kick. At first I was depressing it about a half kick like the guy at the dealer showed me, but once I started going only about one inch it started all the time. 3) I find that when I'm worn out I have trouble kicking it over because I am not getting a good solid kick due to no more leg power. Since the bike is so tall and it is hard to get good leverage for a solid kick, I will stand my left leg on the nearest incline, tree root, or whatever so I am higher up and can give it a good kick down. May sound stupid but works every time.

also make sure your idle is up high enough so it starts easier and isnt as prone to stall on slow berms...hope this helps solve yo problem!! Oh yeah my 01' 426 was hard to start until i got about 15 hrs on it then it loosens up and you can feel it get faster and easier to start!! Take the stock denso plug out and replace it with an NGK (denso's suck and foul reral easy)



I get my kicks on a 2001' YZ426!

Friendswood, TX

Sorry, I threw one too many "release it" in there. Find top dead center, pull in decompression lever, depress kickstarter one inch let go of lever and release kick starter back to top then kick.

I also forgot to mention that I use the choke only for a completely cold start. If I stop for 5 or 10 minutes then start again, or if I stall it, I don't even need the hot start button. Just kick it and it starts.

I have it down to a single kik, mabe two on a bad day!


1 put your hand on the brake res. instead

2 open choke

3 pull in decompression lever

4 kik the bike over 4-5 times with the decomp in

5 release the decomp lever and push the kik starter down till u reach the hard spot

6 let the kik starter return to the top of its stroke, keep your foot on it .

7 now the important part, move the kik starter down one inch!!!!!!!

8 return to the top again, make sure you hand is on the brake res.

9 now with a smooth strong kik, push the kik starter all the way through it's stroke.

the bike will start, as long as the gas is on and u have fuel.

Good luk

Hold it Wide...


I just have to jump in and say something.

Last week I tried a 48 pilot jet just to see what effect it would have on off-idle response. The bike was nearly impossible to start. I went back to the 45, and it started first kick every time, (as before) hot or cold, no hot start required. Blah blah blah.

Consider how the bike may be set up.

However, my bike was also very difficult to start when new. I'm not sure if I changed or it did.

Hello med56, Don't give up on it yet! If you tried all the advice in your previous post on the subject, you may have something restricting your fuel flow. Others may debunk my suggestion but I'd check your fuel line and maybe even your carb internally. I can't imagine there being any dirt in there since it's new but something could have found it's way into the tank or carb at the factory or maybe even on the showroom floor.

Kids do the darndest things you know. Hope this helps.



like a kid again, 00426

The bike is brand new.. I haven't even considered changing the jetting as of yet, but it may be a solution. I am still banking on "Operator Failure" as the source of the problem. I must be doing something wrong. I have been riding MX bikes since 1980 and this is the first one I have ever had any problem with. My 1981 YZ465 was a breeze to start compared to this thing!

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