new wr450f and the dealer can't get it to run smooth on the low end

7 replies to this topic

Posted June 18, 2003 - 03:27 PM


please help with a low speed problem, can't give full throttle without stalling.
bike runs extremly rough at low speeds
very hard to start
the dealer has said they have tried many different jetting options nothing seems to work
bike has less than 8 hrs. on it
been this way since the day i picked it up
ready to get it back and try to take care of it myself.

open to any help
rochester, n.y.

  • jwriott

Posted June 18, 2003 - 04:18 PM


I'm not sure what bike you have but if it's a WR or YZ, I'd try a new plug before I did anything.

  • yamahasocal450

Posted June 18, 2003 - 04:32 PM


it might be too rich... try a smaller pilot :D :)

  • nickanthony

Posted June 19, 2003 - 07:39 AM


I would sell the bike to me for $500 bucks and concentrate on my new cabinets for my trailer. :)

Guess Who???

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • RJGilbert

Posted June 20, 2003 - 03:44 AM


Tell the dealer you'll either accept your money back or a bike that runs right. Yamaha better improve their first year quality on new models. It is becoming well known that the general public and unfortunate first year buyers of any new Yamaha products get to sort out their problems. I'll bet the '04s have better dialed in jetting. I've been burned by this in Snowmobiles (Viper), ATVs (Grizzly), Dirt bikes (WR450). Yamaha - ever heard of validation testing, you know that basic engineering principle to prevent junk from reaching the public?

  • jchantzWR400F

Posted June 20, 2003 - 04:18 AM


Your paying money for performance and reliablility (should those to words be used in the same sentence) and not getting either. I can't imagine why anyone would buy a new bike, take it home, have it not run right, and not go directly back to the dealer and demand a refund, or a properly running bike. :D

I argue that Yamaha has not done enough to remedy the problems on the new 450. Yeah, I know they issued the TSB. Big Freaking Deal. Do you really think some dealer who has carrried 2-3 450's this year give's a s*#t about properly doing the TSB, or even has mechanics trained to do the TSB? In fact, do you really think yamaha gives a s*#t about wether or not the TSB was done properly? I mean, they've already sold the bike to the dealer. They just issued the TSB to cover they're ace because they know they had a manufacturing/design problem. :)

I know this doesn't specifically address your more than likely jetting problems, but it does address problems with yamaha in general. I just refuse to believe that you can't purchase a new yamaha (and expect it to perform) without having to do the "free mods" and re-jet, and having a TSB done (that might not work in the first place). If yamaha is going to expect everyone who buys their dirt bikes to do all this crap, they ought to start selling them for about $3500-$4000 instead of $5500 to $6000. Then they can tell you to spend the extra money to get the damn thing to run right. They should also say, "Oh buy the way, don't expect to spend a lot of time riding the thing right away, you'll have to shave the throttle stop, remove the air-box lid, cut a couple wires, open up the exhaust (then put an insert in so it won't be loud as hell), or put an aftermarket exhaust on (your choice $200-$500 bucks), then you'll have to rejet it yourself, or pay someone to rejet it (which is no easy task). Then, you'll get to ride it for a while until the woodruff key shears because of a manufacturing defect. Then bring it back to the dealer and they will fix it (hopefully the first time). If they don't just bring it back again. We don't want to give you a refund, or a new one, we'd really just like to try and fix it. Then you can ride it and see if you're jetting is right. What should the jetting be? Well, we really don't know. If it's off, just keep changing it until it runs right. I hear you can get on a website called and a guy named Taffy can help you out, but we (or yamaha) really can't. Good luck with the new bike, I hear once you get'em set up, they really rip."

  • lipskid

Posted June 21, 2003 - 03:16 PM


Furnwood- Don't worry, you're going to love this bike. Have them disconnect the grey wire coming from the ECM. Mine ran very rough on the low end until I did this. This wire alters the ignition curve so the bike will run with all EPA garbage in place. Also try a 48 or 50 pilot and 160 main to start with, or look around this site and see what jetting others are running. :)


Posted June 22, 2003 - 12:17 AM


:thumbsup:thanks for the info
I told the dealer a few days ago to put in a 48 pilot and 160 main and then I went into their shop and took off the tank and cut the grey wire myself, they thought I was crazy.
I brought it home runs great !!!!!!
turns out the dealer found a dealer tech mod upgrade book (by yamaha) and they had step by step text and pics to do the same things. take out the baffle,cut out the air box, and cut the grey wire. :excuseme:WHAT DOESN'T ANYBODY READ THE MANUALS???????????




Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.