Factory carb settings

7 replies to this topic
  • kev-in-spain

Posted November 23, 2014 - 05:02 AM


Hi all,

Can anyone here tell me the factory carb settings for a European 2005 WR450F? i.e. jet sizes, needle setting, air mixture screw setting?

I've bought the bike with a bunch of mods done to it and it runs really rough. I need to get everything back to standard and start again with a clean slate.





  • Krannie McKranface

Posted November 23, 2014 - 06:33 AM


You don't want the stock settings, as they are extremely lean.

If the bike has an aftermarket exhaust or an opened top airbox, you must use modified jetting, or you will run even leaner.


Most commonly, the pilot gets partially clogged, so start with just replacing that, if you want. 


With non stock exhaust:




NCVS needle 3rd

50 leak

stock power jet

stock main air jet


Does you bike have the ACV on the side of the carb ( a 3 screw cover near the top)


Also, buy a R&D or similar remote fuel screw so you can easily adjust the fuel screw

  • Krannie McKranface

Posted November 23, 2014 - 06:34 AM


You can download a service manual for free from yamaha's site

  • kev-in-spain

Posted November 23, 2014 - 09:18 AM


Cheers Kah Ran Nee.

The bike does have a Titanium after market exhaust on it but I'm not sure what other work has been done. Someone has put duck tape over the side air intake and the thing will not tick over without constantly blipping the throttle. It pops and bangs on the overrun like you wouldn't believe and misfires under acceleration.

My intention is to put the standard exhaust back on, set everything back to standard and start again from there.

If it runs ok, I might even leave it standard as I want to use it on the road for a while and don't fancy drawing the attention of the local law enforcement chaps :-)

I'll download the manual and get the standard settings from there.


Thanks again

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  • Team_Oatmeal_Pie

Posted November 23, 2014 - 10:11 AM


Sounds like a plugged pilot jet. - wont idle - pops and runs erratically - back fires.

If bike has been sitting for awhile - Drain gas tank

Also take flash light take a look into the tank see if you have any sludge accumulating in there-

  • Krannie McKranface

Posted November 23, 2014 - 04:52 PM


Do not put the stock exhaust back on without modifying it to remove the 'pea-shooter' end piece. It will make the bike run too hot and too lean.


Read the FAQ's

  • kev-in-spain

Posted November 24, 2014 - 12:19 AM


Thanks guys. The bike had been sitting for a while so I'll drain the tank and give the carb a clean. Where do I find theFAQ section? Sorry, new to this site and don't know my way around it yet.

  • Krannie McKranface

Posted November 24, 2014 - 05:10 AM




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