new wr450 breaking down.

[T revv]

Hi all

First post, hoping someone can help. My WR 450 second day old and is missing ,or as you would say breaking down at midrange, throttle when you hold it steady like it is starving for fuel, been jetted by the bike shop to what they say is standard on pre delivery. has plenty of stick after this spitting and farting from mid range onwards, bike shop seem to think it is dirty fuel. any help would be great,cheers.

[strtdsmallproject]

Ive had problems with the primary jet getting clogged easily. It acts just like u describe. It happens a couple of times in a year. I swear these 4 strokers are carb sensitive. I just pull the carb pull the jets and screw blow it out and start again.

[T revv]

Thanks for the info its good to have some direction before I pull it apart, I may not need to dig as far as I thourght.

[1talbotj]

my wr has constant problems with jets plugging up, i swear if you let the bike sit more than a month i have to pull the carb and completely clean the garbage out of the leak jet...

[CanadianWR450]

Do a search on "TPS Stutter"

[MANIAC998]

I've gotten a bad batch of fuel before, and it did just what you described. I suggest trying a new batch of fuel before tearing anything apart. Maniac

[ur2silly]

I agree with the dirty fuel scenario. Hasn't happened yet on my WR but it has happened with my ATV before. What year WR do you have? Since it is such a pain to pull and clean the carb on the 07+ I suggest you change out the fuel and first try running some Sea Foam through it. You can pick up Sea Foam at pretty much any auto parts store. Just follow the directions on the bottle. Might save you a few hours labor if the carb is not clogged too bad. That stuff is MAGIC!!!

[1talbotj]

sea foam?

Edited August 26, 2011 by 1talbotj
wrong spelling

[ur2silly]

Yes, Sea Foam. It is a brand name of Carburetor/ fuel system cleaner and conditioner. Probably will not work if the fuel was full of dirt or sand but for a bike that has set for a while and the fuel has evaporated and left "varnish" in the carb it is the bom-diggity. This stuff really works. No, I am in no way affiliated with the company, just passing along info. about a product that actually works as advertised.

http://www.seafoamsales.com/

[desertlover]

Do a search on "TPS Stutter"

Make sure she's jetted properly, do the grey wire mod, I just unplugged my TPS. I don't know if it completely goes away, but I don't notice it much any more. ?

Basically, the carb likes a varying throttle, and not a constant speed. You probably have a factory street legal version? When your ready to really rip, do the yz throttle stop!

These are great reliable bikes, but have a few quirks, like chainslap!

[CanadianWR450]

Make sure she's jetted properly, do the grey wire mod, I just unplugged my TPS. I don't know if it completely goes away, but I don't notice it much any more. ?

Basically, the carb likes a varying throttle, and not a constant speed. You probably have a factory street legal version? When your ready to really rip, do the yz throttle stop!

These are great reliable bikes, but have a few quirks, like chainslap!

I never notice the stutter in the dirt, but I have just DS'd mine, and notice it on the street. I have also noticed on my bike it is VERY sensitive to fuel screw settings, and if the fuel screw is a bit lean, it makes it much worse. I also find it much worse when the bike is not under any load, like pulling away on the street in 1st or 2nd easily. I'm at the point now that between making sure the fuel screw is right, and adjusting my riding style in the upper gears (don't hold it steady, even the most minor throttle fluctuations eliminates it). it's not a issue at all except the first two gears with little load.

Coming on to it in first and second like I would normally do in dirt, (and it NEVER stutters) is very inadvisable on the street...lol