08 450

4 replies to this topic
  • 00LS1SS

Posted February 04, 2009 - 12:29 PM


Hey there guys , I would like ur advice on me going to a 155 main from a 160, stock needle 2nd from top(which is 1 up from stock),stock 45 pilot and leak jet and my fuel screw which will be played with of course. I am at 2000-3000ft elevation and temps anywhere from 0 deg celcius to +30 Celcius. I know many are using a 165 main at sea level which is a jump up from stock so I am sure a 155 for being higher isnt a huge deal, just curious on advice so i can attempt being as close as possible first time out this spring.I should probably go down a notch on the pilot as well.Bike is stock 08 yz450 with wirtz accel pump cover and stock pipe right now.Thanks for any tips as i have yet to do any jetting on this but i did foul a plug at the end of last year in the mountains on a hot day.Cheers:ride:

  • 00LS1SS

Posted February 04, 2009 - 09:18 PM


Oh well no one replied so ill answer to myself...Hey self !!! 2 out on the screw and this thing picked up its head and laid waste to the yet half frozen dirt, power everywhere,snappy response and started on the first kick every time,1 or 2 down on pilot and it"ll be even better, checked valves and were all exact same for their respective side(intake/exhaust),
Myself: go out and buy yourself a pipe and things are probably really going to change again !! G'night,
Me: your welcome...
Me: No problem

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  • Wiz636

Posted February 05, 2009 - 02:28 PM


Well...you are asking for jetting recommendations to deal with a HUGE temperature variable and 1,000' elevation variable so I think that's why nobody is taking a shot at it.

If you are running good with two turns out on the fuel screw then I would leave your PJ alone for now since spring is coming. Once you get down to about one turn out on the fuel screw as things warm up then I would drop a size on the PJ. In the meantime, I am assuming it is pretty cold where you are so I would put the needle clip back in it's stock position.

Also, check out the great jetting data base sticky thread http://www.thumperta...ad.php?t=694921

  • Kalar01

Posted February 05, 2009 - 06:28 PM


If this will help I ride 5,000-10,000 ft with a 148 main 45 pilot in summer & 48 in winter (all lower altitude in winter)

  • 00LS1SS

Posted February 06, 2009 - 10:45 AM


Thanks wiz636 , looks like that makes sense I'm trying at least the 42 pilot anyways and ill redo the pilot test since i put it in already,plus with the 45pj and fuel screw in all the way it kept running. I probably wont ride a whole lot untill it gets a bit warmer anyways.
Kalari, im surprised at that elevation u still use the 45pj...how many turns out r u with your fuel ? 1 id guess max ?

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