Exhuast is melting air filter box

57 replies to this topic
  • 03yzf450-kuke

Posted April 14, 2015 - 05:17 AM


There is a procedure for setting up your idle properly in the manual. You can tell by using air fuel screw adjustment if you need to change jets up or down size

  • 03yzf450-kuke

Posted April 14, 2015 - 05:18 AM


I don't know why gray racer isn't jumping in to help you instead of just correcting me lol

  • RPS444

Posted April 14, 2015 - 06:11 AM


So is it the Pilot jet that would need to be tweaked? I read up a little and that's the one that supplies fuel during idle. Also I'm assuming we could mess around with the fuel to air as well.

  • RPS444

Posted April 14, 2015 - 06:13 AM


Another thing we noticed which seems to be off is that I have to give at least 2 full throttle's when starting. I heard that when starting you really shouldn't have to give it throttle so is that out of the ordinary?

  • 03yzf450-kuke

Posted April 14, 2015 - 07:20 AM


You aren't supposed to use throttle while kicking it will kick back hard. But yes pumping the throttle a couple times before kicking is proper acc pump will just pump some fuel in to intake to help start

  • 03yzf450-kuke

Posted April 14, 2015 - 07:22 AM


Look to your manual about setting AF screw as that will help you determine what pilot jets to use

  • RPS444

Posted April 14, 2015 - 12:27 PM


Unfortunately I don't have the manual but I read in another forum that the AF screw which is actually fuel not air could be one of the big causes of a hot pipe. Obviously at this point I have learned that the header should glow but def not the mid pipe. I'm going to mess around with the AF and see what happens.

  • William1

Posted April 14, 2015 - 12:31 PM


Fuel Screw/Pilot Jet
Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method. Do it with the bike fully heated up.
Gently turn the fuel screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle knob to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly).  Once warmed, slow the idle speed (knob) to the lowest possible speed.
*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***
Turn the fuel screw in until the idle becomes rough or the bike stalls.
if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.
If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.
Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.
If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.
If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.
If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,850 rpm, but go by the spec in your manual.

  • RPS444

Posted April 15, 2015 - 04:48 AM


Thank you!

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  • 03yzf450-kuke

Posted April 15, 2015 - 05:23 AM


Let us know when you get it figured out

  • 03yzf450-kuke

Posted April 15, 2015 - 05:25 AM


And make sure there is spring then washer then oring(good condition) on fuel screw.damaged o ring on fuel screw can cause lean conditions as well

  • RPS444

Posted April 15, 2015 - 09:57 AM


After replacing the water pump o rings does the system need to be bled? We couldn't figure out but thought there could be air in the system.

  • 03yzf450-kuke

Posted April 15, 2015 - 11:28 AM


Just pour the coolant in full and run itfor a minute then shut down and top up and it running hot that way won't make your midpipe glow so don't get the idea that it could be the cause if there was an air lock

  • RPS444

Posted April 17, 2015 - 03:42 PM


Does this bike use an air screw or a fuel screw? Just double checking. Its idleing high and popping alot

  • RPS444

Posted April 17, 2015 - 04:16 PM


The way we have it running the best right now is with the screw almost all the way in.

  • 03yzf450-kuke

Posted April 18, 2015 - 04:18 AM


Its a fuel screw so in is leaner out is richer

  • 03yzf450-kuke

Posted April 18, 2015 - 04:21 AM


Sounds like you need to re jet pilot circuit. Download the manual free online and refer to the carburetor tuning section. Its always good to have the manual for your bike and it never hurts to read the whole manual on spare time to learn your bike inside and out

  • 03yzf450-kuke

Posted April 18, 2015 - 04:28 AM


You can also refer to what William sent you couple posts back

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