WR450 cant adjust fuel screw - too lean?

6 replies to this topic
  • the_smoo

Posted December 31, 2010 - 11:05 AM


Installed a adjustable fuel screw in my 08 WR450. All stock except for ais removal.. Trying to dial in properly. Bike is a pig to start after it sits for a period. Once started, doesnt like starting with the E-start unless the choke is pulled out ever so slightly. Thats even after warm. Needs to be pulled about 1/4 to 1/2 way and it fires up straight away.

Tried to set the fuel screw as per the sticky. I can screw the screw over the whole range and dont notice any discernable difference. If I screw all the way in, bike dies straight away. Still pops on decel.. thinking too lean a pilot?

Didnt install any of the jets in the GYTR AIS kit as I had read they make the bike run too rich.. thoughts/ideas/opinions.

Outside temp around 50...

  • William1

Posted December 31, 2010 - 12:40 PM


If the bike stalls with the fuel screw just closed or almost closed, that is a sign the pilot is correct. Some bikes, either stall or seem fine, all or nothing. Other bikes, a preceptable difference can be discerned as you move the screw. More so on bikes with ACV activated still.
Set the fuel screw opened as little as possible and have a good idle.

It is possible your idle is too high when setting the fuel screw so much so that you are also on the needle a little. Try lowering the idle speed.

Not sure how long you consider sitting for so no opinon there.

  • the_smoo

Posted December 31, 2010 - 12:57 PM



thanks, will give reduce idle speed and see if its any different.

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  • the_smoo

Posted December 31, 2010 - 01:43 PM


reduced the idle to as low as the bike will take without stalling.. same deal with the screw... dies just on closing..

I have set it at about half a turn out.. seems to be idling nice now and the return to idle after revving is definitely smoother and quicker.. now need to find the best idle setting for the rekluse...

thanks william1:thumbsup:

  • William1

Posted December 31, 2010 - 01:46 PM


When setting the fuel screw, you want the idle as slow as possible.
You tweak the fuel screw to make the bike run as fast as possible. Then go back and reduce the idle speed if possible and again, re-visit the fuel screw and see if you can make it run faster. Keep doing this until the idle speed is reduced as much as you can and the fuel screw is making run as fast as you can. Sort of a balancing act. Then..... you can increase the idle speed to a 'normal idle'.

  • the_smoo

Posted December 31, 2010 - 02:03 PM


that makes a lot of sense... happy new year mate!

  • William1

Posted December 31, 2010 - 04:13 PM


You got it!


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