cant find TDC on my 426 (sometimes)


11 replies to this topic
  • slammmin72

Posted April 15, 2007 - 05:42 PM

#1

i have had the bike for about months now, and i know the drill, always fires first kick. until recently. sometimes, and only sometimes, i go to start it, and normally TDC is pretty obvious, u can just about stand on the kickstarter and it wont budge. not for some reason every now and then, when i go to start it, it feels as iff the decomp. lever is pulled in 1/2 way. i cant find it if im carefull, but the decomp lever isnt needed to push the kickstarter just past TDC. someone please help. maybe i just need to adjust my valves? i checked the decomp lever cable, and it isnt binding or hangin up at all. thanks.

  • King_Air

Posted April 15, 2007 - 06:20 PM

#2

Is the decomp lever cable adjusted properly? Does it have any free play?

  • grayracer513

Posted April 15, 2007 - 06:42 PM

#3

Check your valve clearance. If that's OK, have a leak down test done.

BTW, the "hard spot" you're referring to incorrectly as TDC is the compression stroke at the point where the intakes close, roughly 70 degrees before TDC.

  • slammmin72

Posted April 15, 2007 - 08:09 PM

#4

ive never adjusted it, so i wouldnt know, its worked perfectly since i got it, and its hard to beleive that it could have streched with such minimal use. plus wouldnt the bike preform poorly if the cable was too tight? and u wouldnt be able to kick it over if it was too loose. right? thanks grey, ill have to check those tomorrow. wish me luck, its my first 4stroke. lol.

  • torqueme

Posted April 16, 2007 - 12:01 AM

#5

While you've got the valve cover off do yourself a huge favor & install the '03 auto-decomp mod. It will only take you an extra hour & $110. You'll never have to worry about finding TDC again.

  • robg

Posted April 16, 2007 - 12:16 AM

#6

Yea Auto decomp:applause:

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  • Dustin_Mabro

Posted April 16, 2007 - 09:52 AM

#7

While you've got the valve cover off do yourself a huge favor & install the '03 auto-decomp mod. It will only take you an extra hour & $110. You'll never have to worry about finding TDC again.


+1
the only reason i came here to comment :thumbsup:

  • slammmin72

Posted April 18, 2007 - 05:04 PM

#8

i dont mind the manual decomp lever, i can usually start my 426 faster than my brother can start his CRF450R, and almost as fast as i can start my YZ250.

  • robg

Posted April 18, 2007 - 05:41 PM

#9

I thought I was pretty fast on the old de-comp lever. Until I met my new 03 450 exhaust cam.

  • King_Air

Posted April 18, 2007 - 05:58 PM

#10

I thought I was pretty fast on the old de-comp lever. Until I met my new 03 450 exhaust cam.


Exactly :thumbsup:

  • grayracer513

Posted April 18, 2007 - 07:48 PM

#11

I was raised on manual compression releases. I learned how to start big singles (500-600cc and larger) in 1968, and I am intimately familiar with every trick you can do with one. The first time I rode a YZ426, I started it first kick. I almost didn't buy a YZ450 because they didn't have a compression release.

Do I miss having one? Not for a second. The first time you kill the engine going into a turn and restart it by just letting off the brake, or bump start it at 4 mph, you'll be sold.

  • TotallyMetal

Posted April 18, 2007 - 08:16 PM

#12

I thought I was pretty fast on the old de-comp lever. Until I met my new 03 450 exhaust cam.


Well put. I also thought I was quick on the draw... whew, what a relief!





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