Cdi ?

7 replies to this topic
  • paullywog

Posted July 25, 2011 - 08:11 PM


hi i got a 05 yz450f with a White Bros carbon pipe i read on this forum about some one with the same kind of probs but hear i go. got the bike it ran good for a few days and then it died befor i hit a 75 foot step down (it hurt)and it sounded like the carb. went trought it real good cheched the vales there good i had it runnig the other day pretty good after it was hot it just did not want to start it was firing but just didnt start got tiered came back next day and it fires right up it has a 45 piolet jet 168 main if i get the jd jettingkit will it in clude the stuff to fix it i live at 2600ft elv i just want it to run right i wish i could check compression i would but it has a automatic compression release please help

  • William1

Posted July 26, 2011 - 03:45 AM


???? Could you please use punctuation and proper sentence structure? What you wrote hurt my eyes.

From what I gather, you have inconssitent running problems. Sometimes it runs fine, other times not at all. If so, it is not the jetting. More likely:
  • Bad fuel
  • Worn Cam chin
  • Bad Stator
  • Bad Spark plug
  • Bad coil, cap or wire
  • Poor electrical connection someplace

  • paullywog

Posted July 27, 2011 - 12:33 PM


i got a 05 yz450f it has been giving me shit im down to the cdi i live i the boonies there are lots of trails i want to ride. so my buddy has a 426 is the cdi the same? and if not what is a good brand to get im not a racer jump and trails are my thing so what should i get i dont like the sound of the racing cdi's cuz the rpms (dont wANT TO BLOW IT) so i se them on ebay but i read about people getting bad ones help me please

  • William1

Posted July 27, 2011 - 12:36 PM


CDI's rarely fail. More often it is the stator or coil.

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

Posted July 27, 2011 - 12:44 PM


it runs good for 20 min it gets hot and is hit and miss do wires get loose some were

  • paullywog

Posted July 27, 2011 - 12:59 PM


Sorry I suck at the spelling i drive a tractor and scrap metal for a living and im new to the forums but the bike shop said cdi, coil same thing right? the shop told me if the stator was bad it would not just stop most likely? but i would like to check any thing i can loose connection? were should i start and how?

  • William1

Posted July 27, 2011 - 02:51 PM


Driving a tractor and doing scrap is not excuse (I bet I sound like your mother) for poor communication skills. Trust me, they are valuable.

You need to find a better shop. Stators orten manifest failures by first causing a high speed miss that over time, gets worse. It also tends to get worse as the bike get s hotter.

First check every connection, ensure all are clean and solid, that means each pin.
Then get your manual out and follow the tests in it. Now, a stator can test ok when cold when the failure happenes under load. But they do fail 100 times more often than CDI's. TRut be told, the only CDI's I have ever replaced were ones that a persdamaged in a crash or they were screwing with the wiring and they did something really stupid. But stators, igntion coils, all reside in a brutal place and are fairly fragile items.

I am going to merge this thread with the other one you started on the same subject that now resides in the YZ450 forum. Please only add to this thread and do not start any new ones. You are making some of use answer the same question more than once.

  • ttr250dude

Posted July 27, 2011 - 03:07 PM


I agree it sounds like electrical, but as a side note; try throwing in a 48 pilot and 165 main. Is your fuel screw more than 2 turns out?

Related Content


Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies

05 yz450f not fast enough by RedeyeYZ

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

WR Camshaft Swap Info

  • 0 replies

Should I buy this bike? help....... by Numsa Hul

Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • * * * * *
  • 10 replies

Yamaha YZ450F 2017 by Chris.GVS

Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017

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.