2005 WR450 misfire

My 05 has about 50 miles on it and has seen mostly slow speed trails. I found a fire road this weekend and opened it up in 4th and 5th. It bogs when you go to full throttle and misfires at higher RPM. The only thing I've done to it is cut the throttle stop per the FAQ. I did let it idle with the choke on for about 2 minutes. Would that have fouled the plug?

Unfortunatly I don't have any great info for you but I'm curious to know, is this a CA bike? If so I'm sure it's probably too lean, might be a cause? I'm sure we will all learn more about the '05's as time passes on.

Brian, as you're new on here & don't have any info in your profile I have no idea how much thumper experience you have, but it seems to me alot of the CA bikes run lean, as stated by Endurordr, but I'm wondering if this "misfire" at higher RPM might not be the rev limiter? I know the first time I hit the rev limiter on a thumper I thoght the thing was going to explode! :cry:

My 05 has about 50 miles on it and has seen mostly slow speed trails. I found a fire road this weekend and opened it up in 4th and 5th. It bogs when you go to full throttle and misfires at higher RPM. The only thing I've done to it is cut the throttle stop per the FAQ. I did let it idle with the choke on for about 2 minutes. Would that have fouled the plug?

Dont worry about idling it with a choke for a couple of minutes. In the future the bike needs only 30 seconds to a minute and then ride it. :cry: Your bike just needs to be jetted for the current conditions.

Let us know your current jetting, riding area, temps, elevations, etc and if you are running corked or uncorked with the stock pipe. We can then make jetting recommendations. :cry:

Dont worry about idling it with a choke for a couple of minutes. In the future the bike needs only 30 seconds to a minute and then ride it. :cry: Your bike just needs to be jetted for the current conditions.

Let us know your current jetting, riding area, temps, elevations, etc and if you are running corked or uncorked with the stock pipe. We can then make jetting recommendations. :cry:

I'll change my profile to reflect the changes I make to the bike, but here's the skinny as it sits now:

2005 WR450F

Throttle stop cut to YZ specs

Gray wire mod

Removed the 'cork' from the muffler

I ride at 1100 feet elevation and it's about 80 degrees this time of year.

I did the gray wire and cork mod last night and will ride it tonight to see if I made it better or worse.

As for jetting, I have no clue. It's however it was delivered to the dealer.

Based on those conditions I would run 160 main, stock needle in clip #4 from the top, 48 pilot. Try a new plug at the same time you may have fouled up the one that is in there. :cry:

The latest info, but first a big thanks to all who suggested the gray wire mod. It DOES work on a 2005 WR450.

Anyway, I did the gray wire mod and took that snorkle thingy out of the pipe. It's all happy now, and runs like a champ. So, for those of you with 2005s wondering if all the old mods work...they do.

The latest info, but first a big thanks to all who suggested the gray wire mod. It DOES work on a 2005 WR450.

Anyway, I did the gray wire mod and took that snorkle thingy out of the pipe. It's all happy now, and runs like a champ. So, for those of you with 2005s wondering if all the old mods work...they do.

Did you re jet it too?

The latest info, but first a big thanks to all who suggested the gray wire mod. It DOES work on a 2005 WR450.

Anyway, I did the gray wire mod and took that snorkle thingy out of the pipe. It's all happy now, and runs like a champ. So, for those of you with 2005s wondering if all the old mods work...they do.

Yes I made that suggestion on the jetting forum for your same desperate post and some guys thought I was nuts. Glad to see the wires are there. Your dealer was wrong about the wires! :cry:

Yes I made that suggestion on the jetting forum for your same desperate post and some guys thought I was nuts. Glad to see the wires are there. Your dealer was wrong about the wires! :cry:

Yeah, turns out my dealer was wrong on a great many things :-(

Anyway, no rejet until I take the snorkel out of the airbox. Rumor has it it'll be a bit lean but maybe I can cheat and just change the needle.

I'm not doing ANYTHING else to it until I figure out how to ride the damn thing!

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