wr450 backfire on decelaration
Posted November 10, 2006 - 06:06 PM
Posted November 11, 2006 - 02:22 AM
Posted November 11, 2006 - 10:21 PM
Posted November 19, 2006 - 02:10 PM
Posted November 19, 2006 - 03:34 PM
I've got a 172m, and it still backfires. I wouldn't worry about it.
changing a main jet wont affect backfiring on decelleration. That is where the pilot jet comes into play. try a larger pilot jet.
Posted November 19, 2006 - 04:02 PM
Posted November 19, 2006 - 04:45 PM
Posted November 19, 2006 - 08:43 PM
I have a huge pilot jet on my bike and she still backfires on decel with the fuel screw at anything less then 3 turns out, but then i get alot of black smoke on initial acceleration. can't win them all (without fuel injection)
Try one up on the pilot and one down on the main
Posted November 20, 2006 - 08:42 AM
Posted November 20, 2006 - 09:24 AM
first off, what year is your wr? if you have the ais on your bike, it will pop a bit on decel. it's not a lean condition as much as how the ais works. if you don't have the ais ('03-'04), you should consider your jetting. running a 48 pilot jet is a good base line number and should take care of the popping. if you run a 48 and do not have the ais, it will be harder to find. you will be looking for an air leak. make sure the hot start cable is not kinked and not letting the plunger seat.
I agree. Another thing to check for is a clogged up pilot jet. I was running a 48 and early in the year it started popping on decel, running hot, and really surging a constant low throttle speeds.
Being a newbie, I didn't know where to begin. But after many SEARCHES, I kinda narrowed it down to the pilot jet. I pulled it out and ta da, it was clogged up with gunk. Once cleaned out, the bike was back to normal.
P.S. The people here are amazing, but please do a SEARCH before asking any questions. And if you do ask a question, please provide more details about your bike.
Posted November 20, 2006 - 11:34 PM
Posted November 21, 2006 - 11:02 PM
I do know that carb jetting on a wr450 has little to do with backfires unless you scrap AIS and do the carb mods in "..Performance Mods" thread which effectively reduce backfiring. I have done ALL the mods listed and still have a few backfires. I have a 45 pilot....1-1/2 turns but I'm at 3500 ft.
Posted November 27, 2006 - 09:49 PM