decomp cable snapped

3 replies to this topic
  • ickers11

Posted July 04, 2014 - 02:36 AM


Hi all,


Ridden my 01 yz426 for about 15 hours now and getting used to it. its an absolutely outstanding bike, love it to bits.


Anyway, after having a little whoops moment and had to restart the bike. Anyway, i pulled the decomp lever and it went limp (no tension) so the cable must have snapped, had a little look at in on the track and the top end is still connected so it must have snapped where it connects to the engine.

I still started it and rode it and also started it the next day from cold (with a little bit of trouble) but definately want to get the decomp lever back working.

So my questions are, has anyone ever had to replace this cable, if so, how hard is it? Also, despite the fact that its hard, is trying to start it without using the decomp lever bad for the bike? 

Thanks in advance.


  • Thommo_400f

Posted July 06, 2014 - 05:07 PM


Decomp is only to get piston a hair past TDC.

Just be sure to push kickstart down and hold it firmly until you feel it squeeze past TDC. Then kick it properly.

Slower but safer.That way you won't get a half assed kick in that hurts your ankle or puts undue strain on kickstarter.


Cable replacement is really easy.

Either replace cable or get '03 cams which have autodecomp.

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  • G-BRO

Posted July 06, 2014 - 06:20 PM


Word to the wise-

Pay attention to where the cable is routed before removal. The Yamaha manual has a cable routing diagram. I once incorrectly routed this cable on my 01. When I turned the handlebars full left it pulled on the cable causing the motor to stumble and sometimes die all together. Of course I didn't figure this out until I was 200 miles from home.

  • grayracer513

Posted July 07, 2014 - 06:34 AM


Decomp is only to get piston a hair past TDC.

Just be sure to push kickstart down and hold it firmly until you feel it squeeze past TDC. Then kick it properly.


How I wish people would stop saying that.  It's not TDC.


"TDC" is Top Dead Center.  The resistance that you feel in the crank as you turn the engine is from the beginning of the compression stroke, which happens 110-120 degrees BEFORE TDC.  The lever is pulled, and the kick crank advanced about another inch, which moves the piston farther up the bore, closer to, but NOT past TDC. (exactly what is accomplished by the auto decompression systems). The spark occurs just before TDC.  If you were to go past it, the engine would need to be turned two complete revolutions and pass through a complete compression stroke before getting back to the ignition point again.

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