04 wr450 carb problems- help please
Posted April 02, 2015 - 01:16 AM
Posted April 02, 2015 - 04:39 AM
There is never a reason to change jetting on a previously well running bike.......jetting requirements do not randomly change.
Replace the pilot jet with a BRAND NEW ONE and clear the passage above the jet with fishing line and spray cleaner
Get an R&D remote fuel screw for proper adjusting
If you are going to remove the carb, you should also do the required maintenece:
- new slide plate seal
- needle jet replace
- clean/polish/lubricate the hot start and choke plungers and cavities
- apump verify (nozzle spray, free moving check ball, etc)
Edited by Kah Ran Nee, April 02, 2015 - 04:40 AM.
Posted April 02, 2015 - 11:44 AM
Posted April 02, 2015 - 02:25 PM
You can't get it all out without an ultrasonic cleaner.....or by damaging the fluted openings.
Posted April 03, 2015 - 04:29 PM
I would think he loosened some dirt up somewhere last time, which is now plugging the pilot circuit. Or maybe unknowingly lost the fuel screw o-ring.
Tell him to blow some carby cleaner and compressed air through the passage behind the pilot jet - if he sticks his finger over the tiny hole that sits just inside where the carburetor connects to the engine, you should be able to feel the pressure from compressed air that is being blown into the pilot passage.
Secondly, take the fuel screw out and double check that all the bits for it are still there. If he's missing the o-ring it will cause bad idle. Careful as sometimes it's just stuck up there. Clean out behind up there as well. It's definitely a good idea to buy an aftermarket one as Kah Ran Nee said. They are pretty cheap.
Hope that helps out.
Posted April 09, 2015 - 09:58 AM
Posted April 09, 2015 - 11:17 AM
Because there is still corrosion inside the carb; probably the pilot passage, so it is acting lean, still.
Posted April 09, 2015 - 01:30 PM
You can do that, but reaming the passage above the pilot jet with strong solvent and a large fishing line usually does it.
You must remove all rubber and foam parts form the carb before attempting this....
Posted April 09, 2015 - 03:43 PM
I made this mistake myself.
It looks like it should go the other way but doesn't.
It popped bad on decel like this. I mean bad!!