06 backfires no start


10 replies to this topic
  • TwIzTeD NuTz

Posted December 20, 2011 - 02:41 PM

#1

I have an 06 YZ450 that it will no longer start it only back fires. where should i start? timing has been checked, valve clearances adjusted,carb gone through. it just back fires through the exhaust. any input??

  • grayracer513

Posted December 20, 2011 - 04:29 PM

#2

When you checked the timing, did you verify that the marks on the flywheel were aligned with TDC?

  • 2grimjim

Posted December 20, 2011 - 04:36 PM

#3

Silly questions;

How long since you rode it last?

What's the sparkplug look like?

How old's the gas?

Was this a progressive problem? i.e. Was your bike having hard starting problems that got progressively worse, to the point of not starting at all?

A little history of the problem will help a lot.

  • TwIzTeD NuTz

Posted December 20, 2011 - 05:07 PM

#4

When you checked the timing, did you verify that the marks on the flywheel were aligned with TDC?


timing was verified with the marks on the flywheel and also with the piston.

Silly questions;

How long since you rode it last?

probably last time it ran long enought to ride it was september. I have been fighting this problem since then.

What's the sparkplug look like?

Posted Image

Posted Image

How old's the gas?

gas is fresh. just put it in this morning.
Was this a progressive problem? i.e. Was your bike having hard starting problems that got progressively worse, to the point of not starting at all?

it was getting progressivly harder to start. and then it got to the point that all it would do is back fire, and here i am today asking for some help :bonk:

A little history of the problem will help a lot.



  • TwIzTeD NuTz

Posted December 20, 2011 - 05:08 PM

#5

also, the bike has a vortex ignition, I do not have a stock ignition to swap out to test though.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • capt justin

Posted December 20, 2011 - 05:15 PM

#6

replace that plug with a new one

  • 2grimjim

Posted December 20, 2011 - 06:56 PM

#7

Are you getting a consistant spark at the plug with it stuck in the coil and grounded on the engine?

  • TwIzTeD NuTz

Posted December 20, 2011 - 07:12 PM

#8

Are you getting a consistant spark at the plug with it stuck in the coil and grounded on the engine?


I would not say its consistent, it seems very weak truthfully.

  • 2grimjim

Posted December 20, 2011 - 07:34 PM

#9

I would not say its consistent, it seems very weak truthfully.


Hmmm..... without being able to swap in the stock CDI you'll have to throw the dice and buy a CDI. If you pin check the coil and stator and they spec-ok you really don't have a choice.

Do try replacing the plug first though, if you haven't already done that.

  • TwIzTeD NuTz

Posted December 20, 2011 - 08:11 PM

#10

Hmmm..... without being able to swap in the stock CDI you'll have to throw the dice and buy a CDI. If you pin check the coil and stator and they spec-ok you really don't have a choice.

Do try replacing the plug first though, if you haven't already done that.


I'm picking up a new plug tomorrow, I'm trying to locate a cheap cdi also.

  • 2grimjim

Posted December 20, 2011 - 08:25 PM

#11

I'm picking up a new plug tomorrow, I'm trying to locate a cheap cdi also.


You have oter options other than a stock or Vortex CDI. Dyna makes a programable CDI (not quite as cool as the Vortex) for about $350 (retail). A little shopping you should be able to get one for under $300.





Related Content

Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo

The "going back to the other darkside" adventure... by Monk


Dirt Bike   Make / Model Specific   KTM   250/350/450/505 SX-F & XC-F (4-Strokes)
  • Hot  113 replies
Forums
Photo

05 yz450f not fast enough by RedeyeYZ


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  38 replies
Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.