dirt dragging my yz450f. need some help

5 replies to this topic
  • Blackyz450

Posted May 19, 2014 - 06:26 AM


I have a 2006 yz450f which I have put 12:8 piston in and had the head ported and stage 2 hot cams which I didn't get any faster or better times out of by adding the hot cams.. makes me mad about that.. but is there anyone who also drags plus maybe knows a a site/ people I could talk to for more info on how to set it up better like jetting gearing for this.. and it is also 500 feet I am running..I also fave a open air filter to.. thank you


Posted May 19, 2014 - 06:50 AM


Have you set up your suspension at all , setting it up so you get more traction .

  • Blackyz450

Posted May 19, 2014 - 08:03 AM


yes I have it runs good I think it has more thou... It went 7.2 sec in 500 ft at 81mph


but I think it will go 6.9s like 84 or 85 just think something is not right just seems like its not pulling the hole way though.. it has a 12 on the front and a 48 on the rear and i am leaving and 3 gear wicked

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  • grayracer513

Posted May 19, 2014 - 08:35 AM


Raise the gearing: you're at 10K RPM at 79 mph WITHOUT factoring in wheel slippage.  Power falls off at right at 10K.


Run a hole shot device if you don't already.


Who did the ports?  Do you have dyno tests from before/after?

  • Blackyz450

Posted May 19, 2014 - 05:50 PM


dc cycle and racing did the porter and the also put it on  a flow bench..  it did pick up from last year.. and no i did not get it dynoed before or after.. I think alot is in the gearing  like they say the less I have to shift the better and the longer it can pull though the gear the better but got to find the right gearing I was think of upping the front to a 13 or 14 and starting in 1 or 2 and hope to run like 1 2 3 or 2 3 4 and not sure about the jetting with the  cams and open air filter what i should be I have a 145 pilot jet and the 5th clip on the needle and a 170 main which I need to change the needle because it shouldn't  down that far i don't think.. but I also think being its a open air filter its getting a lot of air I probably need more main. plug where the porcelain is inside the plug was white very white and the electrode was like not white but not far off

  • grayracer513

Posted May 20, 2014 - 05:40 AM


If by open air filter you mean that you have cut away the air box, that won't affect jetting. The air box had no flow restriction issues beyond the resistance of the filter.

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