06 450 carb issue? The

11 replies to this topic
  • ibbw

Posted February 14, 2016 - 05:38 PM


I bought a used 06 and I knew it wasn't running correctly. It saw most of its life in the garage. Tank stunk of old fuel so I dumped it and cleaned it out. Cleaned the carb, changed the oil, cleaned the filter and check tappet clearances. The valves were on the low end but still in spec. I am going to address that this week. Got it back together and it starts but will not idle with the choke off and pops like crazy with the choke off. I can get above 1/4 throttle and push the choke off and it pulls clean to the moon. At closed throttle it pops it's ass off and will run rough till I pull choke knob back on at low speed (1/4 throttle or less)I just saw another similar post where the question was raised if the slide plate had been installed upside down. I'm gonna check and make sure I haven't done the same.

I had to set the idle high, too high. The idle/air screw has no affect no matter where it's set. 1 turn out or 5 turns out. Runs the same. The pilot was stopped up on tear down. It was clean when I went back together. I'm going to investigate to make sure I didnt reinstall the back of the slide upside down first.

It sounds like my pilot circut is still plugged. Anyone agree?

  • vossman23

Posted February 14, 2016 - 06:16 PM


That would be a good start. Cheap to replace.

  • grayracer513

Posted February 14, 2016 - 10:06 PM


You're probably going to have to clear the jet itself with something stiff.  I use the right sized number drill and push it through.  They get partial clogs all the time when they sit a lot.  



  • ibbw

Posted February 15, 2016 - 02:53 PM


Just to put in some info for the next pour sap that has this. The bike ran great as long as it was not idling or decelerating. Rough Idle and also I had to have the idle screw like a half turn from bottoming out. These were my symptoms, for my slide plate being upside down. Remember, Square hole down!! Thanks gray for your help. Your wisdom on here is priceless.

This is exactly what's going on with mine. I'll get see in about an hour if this is what I did too. My fingers are crossed.

  • mach1jonny

Posted February 15, 2016 - 03:50 PM


I agree with you Pilot jet. Also make sure the hot start not open. My son in law has a WR450f and had his hot start cable too tight, so it was partially open. also when lubing the hot start cable - remember to remove it from the carb is the cable lube will gum things up. But your probably right pilot jet clogged.

  • ibbw

Posted February 15, 2016 - 04:22 PM


Front slide upside down

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  • ibbw

Posted February 15, 2016 - 04:47 PM



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  • grayracer513

Posted February 15, 2016 - 05:13 PM


But now it's fixed.  

  • mach1jonny

Posted February 16, 2016 - 08:54 AM


that's a new one, never heard of that before

  • grayracer513

Posted February 16, 2016 - 09:12 AM


Easy mistake.  Happens quite a lot.

  • ibbw

Posted February 17, 2016 - 06:14 PM


Four stroke moto engines are a device of the devil!!! Why did they have to stop making 500cc two strokes?? Exhaust clearances were .001 under minimum. One intake was too. All better now.

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  • ibbw

Posted February 21, 2016 - 04:03 PM


I finally got the carb clean but the real fix was to ream my pilot .0025 bigger. I know that gives some people heartburn, oh well. Buckets shimmed and it runs like a top. No more pop (just one or two very light while gearing down hard) two kick cold start, one kick warm start. Bike has a beautiful power band. Thanks TT.

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