2002 yzf 426 problems

3 replies to this topic
  • 426-unit

Posted October 01, 2006 - 11:25 AM


Hey Thumper talk. I just joined the forums and have a couple questions about my 2002 Yamaha F 426.

My bike will usually start first kick cold, but I'm wondering if anyone has any tips on starting it HOT. I can never seem to get it, even when using the hot start.

I have also heard of getting a hot cam to fix my decompression issue. i hate having to sit there kicking away with my friends all on their new 250f's laughing and starting their bikes with the slightest kick.

if anyone has any tips on starting this beast of a bike, or has any information about taking out the decompression, it would be greatly appreciated.

also, if this has already been covered, it would be great if you could direct me to a couple previous threads.

  • grayracer513

Posted October 01, 2006 - 02:25 PM


The most important thing is to get the idle mixture right, and to be sure your spark plug is in good condition. If both these things are true, it will generally be pretty cooperative IF you start it the right way. You must avoid twisting the throttle, as two stroke riders are prone to do, at all costs. Most 426's will light up with the throttle at idle without the hot start. If that fails beyond the second kick, the hot start should be tried. You may find yours likes the hot start first.

Stalling or crashing tends to leave the bike slightly flooded, in which case the hot start is called for up front. It may even be necessary to open the throttle as far as 1/4 to get it to fire. In extreme cases, opening the throttle near full and holding it there while you turn the bike through a few times with the compression release, if it still has one, or not, if it's been converted to auto decompression, will help by clearing the cylinder. Then close it and try the normal things.

The great thing about the YZ426 is that once you figure out what it wants, it will start that same way for you nearly every time.

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  • 426-unit

Posted October 01, 2006 - 03:22 PM


Thanks for the help. I'll be sure to try that out next time I'm riding.

i was also wondering about auto decompression and whats involved in switching it over.

  • grayracer513

Posted October 01, 2006 - 06:33 PM


Install a YZ450 exhaust cam. Change one part. Done.


The instructions are a JPG. Right click them and save a copy.

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