2007 crf250r won't stop backfiring


5 replies to this topic
  • yamaharider367

Posted 11 July 2009 - 08:40 AM

#1

well to start I haven't been on a 250f since 06 but I missed it so much that i picked up a 2007 for cheap. the previous owner ran race fuel in the bike(not sure what octane i think 110) well i ran that true the bike now im back on 93 pump gas and now it backfires like crazy. every time i ride and let off the gas its just a bunch of backfire. how can i make it stop. bike still runs great just back fires alot.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Nick777

Posted 11 July 2009 - 09:09 AM

#2

jetting, mine did the exact same thing, then i changed the jetting and there is hardly any backfiring, if any at all now.

  • yamaharider367

Posted 11 July 2009 - 02:16 PM

#3

i know this will sound stupid but how do i adjust the jetting. I'm good with tools just never messed with a crab before

  • yamaharider367

Posted 11 July 2009 - 06:10 PM

#4

come on guys help a brother out

  • ebeck

Posted 11 July 2009 - 06:37 PM

#5

Under the carb under the bowl. You can get to it from the 17mm drain plig with out removing the bowl as well. Follow the arrow labeled Pilot jet.
Posted Image

You un-screw it, like this.
Posted Image

It looks like this:
Posted Image


If it is popping when you decelerate you need a larger pilot. 07 with a stock cam you probably need a 72. The pilot size is etched on the pilot jet.

  • yamaharider367

Posted 11 July 2009 - 07:45 PM

#6

thanks. also what exhaust do u have on your 07?





Related Content

Forums
Photo

Recovering 2 VIN digits from my bike by jordanfilbrun


Dirt Bike   Make / Model Specific   Honda   CRF250R
  • 7 replies
Forums
Photo

250f maintenance and repair costs by champie


Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • Hot  37 replies
Forums
Photo

Tokyo Mods VS Eddie Sisneros or others ECU Remapping by BigBlock454


Dirt Bike   Dirt Bike Technical Forums   Intake - Jetting / Fuel Injection
  • 12 replies
Forums
Photo

2012 air4orce airbox on 2011 by avoidthedog


Dirt Bike   Make / Model Specific   Honda   CRF250R
  • 7 replies
Forums
Photo

Street Legal CRF250R by Nate6283


Dirt Bike   Make / Model Specific   Honda   CRF250R
  • 9 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

Register Close
If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.