The Bog!!!!

4 replies to this topic
  • adam918

Posted June 01, 2011 - 11:18 AM


I recently rebuilt my top end. 2006 yz450. New piston, rings, and a pro mechanic did the valve work, replaced the intake valves, seals and cleaned it up. I got it back together, took it to the track to break it in. It starts fine, roll on throttle is great, but it seemed to try to stall going over jumps, which was scary.
I took it home checked the carb. Main is 170, pilot 48. Needle in the middle. Stock leak jet. 2 1/8 turns fuel/air screw. On the the stand while running, if I quickly accelerate, it will bog unless I let off. If I don't let off It will die.
I installed one those Boyesen quick shot 2, the float seemed out of spec, so I adjusted that. Moved the clip down three different times. Now it's back in the middle. Each thing I did still did not take care off the situation. I thought maybe going to a 172 main, but that seems way far away stock main, 165.
I am about ready to take it in, which I really don't want to do. I have trust issues with other people working on my stuff! At this point its a garage ornament. Please help. Thanks

  • grayracer513

Posted June 01, 2011 - 12:07 PM


If you had the bike down for any length of time, you could very easily have a varnished pilot jet. The orifice in a #45 pilot is about .018". A film of dried fuel in that orifice no more than .001" thick will reduce the pilot to the equivalent of a #40-41. They can look clean and you can blow through them, and they can still be "clogged".


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  • adam918

Posted June 01, 2011 - 02:34 PM


Yeah, my bike did sit for a good five months or so. My carb sat on the shelf the whole time. I did take it apart and clean it before it sat. I had to change the water pump seal after I got it back together. It leaked when I fired it up the first time. I assume it dried out ir something from sitting with no coolant.
I'm going to try the the toothpick on the pilot jet and see what happens. Thank You Gray!

  • grayracer513

Posted June 01, 2011 - 03:42 PM


Where does one find .018" toothpicks?

  • dirtdevil72

Posted June 01, 2011 - 03:45 PM


Where does one find .018" toothpicks?

harbor freight

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