05 WR450 Backfiring
Posted February 21, 2011 - 04:49 PM
I asked mechanic if FMF Q2 might need to be repacked, and they said that wouldn't cause the problem.
Any other ideas from the Yamaha Dream Team?
Posted February 21, 2011 - 05:34 PM
Posted February 22, 2011 - 02:26 AM
You could try removing the header, and re-installing, using some silicone, and torquing to spec....
Another possibility could be the pilot jet getting gummed up. Try replacing it.
If it seems to be temp, or weather related it could simply need a bit of a fuel screw adjustment...
Did it just start out of the blue?
Is it consistent, or worse some days compared to others?
How long have you had the bike? If it does it in the winter, but not summer for example, I'd say you just need a bit of a jetting tweak.
Posted February 22, 2011 - 09:32 AM
Do not arbitrarily put in a larger pilot or open the fuel screw. That would make hot starts a nightmare.
Posted February 23, 2011 - 09:27 PM