HELP with starting the 2000 YZ426F

13 replies to this topic
  • EVEL

Posted May 22, 2008 - 02:32 AM


Hey Guys,
I'm new on this line ,just found out about it. Looking for any body who can give me some advise or modifications that will help me start my 2000 YZ426F a little bit easier.... It's a real BEAR to start. Any advise would be greatly appreciated...:thumbsup: .....................EVEL

  • rufusz

Posted May 22, 2008 - 03:08 AM



These are the correct procedures. Installing an exhaust cam with auto-decompressor really helps. You can find plenty of posts on this (HotCams or 450 cam). If still in trouble check for spark/fuel/carburetor. My 426 earlier gave me a lot of trouble because one of the wires coming from the stator was broke/almost broke and sometimes it ran fine/sometimes you couldn't start it no mater what you did :thumbsup:

  • matt4x4

Posted May 22, 2008 - 04:02 AM


If you still have a decomp lever, this is what you do.

Pull choke if temps are below 70 otherwise I find it's not needed.
If it sat for a week or more one twist of the throttle, otherwise no.
push the kick start lever lightly until you can not push it any more - this is TDC
Pull the decomp lever a little bit, push the kick start just a little bit to make the piston pass TDC.
Release the decomp lever, bring kick start to the top, one good strong kick right through.

Bike should fire right up, if it doesn't, replace your plug and possibly you've got some carb cleaning/adjusting to do and will need to read up on how to do that properly.

  • EVEL

Posted May 22, 2008 - 01:32 PM


Thanks for the advice,...............Ray

  • 1rkcooper

Posted May 22, 2008 - 06:41 PM


First off put a new plug in, drain any old gas from the tank and carb if it is old, obviously fill with fresh gas. Fllow the link posted buy rufusz and watch the videos. If you still can't get it to start then you will have to go a bit deeper, I would start by checking the valves and cleaning the carb, out of spec valve shimming will cause a lot of grief.

If I haven't started my bike today I give it three twists of the throttle and then on good kick and it usually fires on the first kick. In my opinion the best thing you can do for a mod is to install an auto decompression cam, cheap ($100-$120) and easy.

There is a ton of info at the top of the YZ forum in the common threads sticky, take the time to read through them.

  • canute

Posted May 23, 2008 - 09:44 AM


What "matt4x4" said, in addition i have had excellent results using an iridium spark plug on my '98 yz400 - one kick every time :thumbsup:

  • Bluzuk

Posted June 01, 2008 - 02:45 PM


mine was an unbelieveable bear to start when I bought it... rode it for 6 months and then I had enough..

I did some research on the proper jetting and then rejetted it... starts 1st kick every time now and has ran unbelieveable since.

the overall power/perforance went way up as expected... I bet soo many are missing out on how good it can run not knowing their stock jetting is so pathetic.

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Posted June 17, 2008 - 05:37 PM


Don't put a 450 Cam in your 426! it tears up the top end! Install a Hot Cams They're a pretty penny but their worth it. Comes With a Automatic Decompression Valve.

  • grayracer513

Posted June 17, 2008 - 06:52 PM


Don't put a 450 Cam in your 426! it tears up the top end!

If that was your experience, I'd say you timed it wrong.


Posted June 17, 2008 - 07:24 PM


Timing was right on the money. i never put a 450 cam in mine.

  • grayracer513

Posted June 17, 2008 - 07:39 PM


If you never had one, what is the basis for your claim that it will cause trouble?


Posted June 17, 2008 - 07:51 PM


The cam chain is narrower on a 426 rather than a 450

  • grayracer513

Posted June 17, 2008 - 09:16 PM


The cam chain is narrower on a 426 rather than a 450

No, actually, it is not, but the tooth profile of the chains and sprockets are different. This causes the 426 chain to ride higher on the 450 cam sprocket than the one it came with. A number of people were originally concerned that this would lead to failures or premature wear, but as I have said, there has been not a single reported incidence of it in this forum in the 5 years since people started using this mod.

It is true that aftermarket cams made specifically for the 426 will fit the chain better, but they cost more, and don't work as well with the original 426 intake as the Yamaha cam does. Since they apparently work, it makes more sense for many than the more expensive aftermarket solutions do.


Posted June 17, 2008 - 09:24 PM


i wanted to change mine beacuse i wanted more power yes i did consider putting a 450 cam in when i first got the bike, but since i had a parts unlimited discount and get them cheap.
i gotta say gray you got your shit together. where dod you learn all this?

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