2004 wr450 with bad backfiring issues
Posted February 11, 2011 - 01:48 PM
Oh yeah he siad the dealer in vegas jetted the bike for local riding but I am not sure of the size of the jet.
Posted February 11, 2011 - 02:42 PM
did you get a manual ?
Posted February 11, 2011 - 02:51 PM
Posted February 11, 2011 - 02:59 PM
Posted February 11, 2011 - 03:16 PM
there are alot of parts in that carb... first one i pulled apart, i laid the parts out in the order they came off...
Posted February 11, 2011 - 03:40 PM
Posted February 11, 2011 - 04:02 PM
Posted February 11, 2011 - 04:15 PM
Not sure if the JD kit includes a new pilot, if not, be sre to get one. Do not bother to try to clean your gunked up one.
I hope it does or I just spent $80.00 bones for nothing, I tried calling them before I ordered but they were closed for the weekend. Could anyone confirm weather or not the kit has a pilot jet so I can cancel my order if not.
Posted February 11, 2011 - 04:45 PM
Posted February 11, 2011 - 04:50 PM
Posted February 12, 2011 - 02:35 PM
It comes with 2 O-rings for the accelerator pump mod, 2 needles (red and blue), and umm...3 main jets? (memory failing me a bit there....) And of course, what your REALLY paying the $80 for...the jetting instructions...follow them to the letter, and do not try to second guess them.
Posted February 23, 2011 - 03:50 PM
Any ideas or suggestions are appreciated, Thanks
Posted February 23, 2011 - 03:54 PM
Posted February 23, 2011 - 04:09 PM
I should have been less lazy and just cleaned the thing the first time I had it off.
Posted February 23, 2011 - 06:11 PM
Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method. Do it with the bike fully heated up.
Gently turn the screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly). Once warmed, slow the idle to the lowest possible speed.
*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***
Turn the screw in until the idle becomes rough or the bike stalls.
if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.
If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.
Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.
If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.
If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.
If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,800 rpm, but go by the spec in your manual.
Posted February 24, 2011 - 01:15 AM
Posted March 09, 2011 - 10:31 PM
Thanks for any input.
Posted March 10, 2011 - 08:17 AM
The backfire on decel is normal depending on how much yours is popping but I'll bet since you're running a bit lean it's worse. I doubt the wire will change much in this instance but I don't have a whole lot of experience regarding how much the map changes.
Posted March 10, 2011 - 10:50 AM