off idle bog

[yamahasocal450]

yea iwent out and played with the accelerator pump screw and when the bike was on the stand in neutral and i gassed it for the first 2 times it would rev cleanly then it would stall... then i took it out for a ride and i lugged it in 3rd gear then i whacked open the throttle then it would pick up then bog then pick up then bog then pick up go a little faster then rip a huge wheelie... that sounds like a pilot air jet to me... but since that is stock im looking at the main air jet but i dont know where that is or if it even exists on this bike

[live_to_ride]

How could it be the pilot air jet if you're rolling along at full throttle while experiencing the problem?

[yamahasocal450]

i actually meant 1/8- 1/2 throttle sorry ?

[live_to_ride]

My bike is almost fine in that range. When I snap to half throttle it only misses one or two beats, then picks up. Cruising at any position is fine. Snapping the throttle from 1/3 to full is fine. Any less than 1/3 and it falls on its face and sometimes takes me with it. ?

[yamahasocal450]

yea i dont know what to do.. when i get all my stuff im going to put in all of the yz jets and start from there because after im through with the airbox it should be as breathable as a yz's...who knows ?

[live_to_ride]

Do you really think that there is a restriction there? I mean the opening in the top is way bigger than the carb opening.

[yamahasocal450]

yea but think about it.. is it easier to suck in air through a tube with an equal diameter or suck in air through a cone with a bigger diameter at the end .. that is why k&n type filters work so well in most applications

[Jonesy920]

I put the yz needle in and my bike ran like crap, but taffy reeled me in with a smaller main/pilot setting. I would try a 150-155 with a 38-40 pilot. Start at 11/2 turns. Clip on 4 to start ?

Did It take out the hesitation from idle to Half. ie; stabbing the throttle and it bogs/dies ? I had the YZ needle in and it was definitly too rich. But now with the weather warming up I am getting the same bog with the stock needle, I am going to try moving the needle clip position. My main is good from 1/2 to full and pilot seems good from 1/4 to 1/2. It is just getting too much fuel when I stab it in too low a gear or Trying to roost my Buddy in the mudd I'm 500-800 ASL

[Motocrash]

See my reply for "WR450 mods only". After all the mods, I can use the fuel screw to adjust out the bog as temp varies. ?

[Taffy]

barking! absolutely barking!

woof! woof!

? :D :D

Taffy