inconsistent


11 replies to this topic
  • Whyzee429

Posted January 30, 2009 - 11:07 PM

#1

my 450 doesn't run smooth when holding a steady throttle. it seems to "surge" if that makes any sense. anyone know what's going on? :)

  • outcast623

Posted January 30, 2009 - 11:13 PM

#2

on my 03 450 mine would almost seem like it was miss firing at constant throttle, I read about it and the consensus is that you should unplug your tps... I tried it and it cleared most of my problem up.

Im sure there is a proper fix for it but this seems to work for me:ride:

  • 642MX

Posted January 31, 2009 - 07:13 AM

#3

my 450 doesn't run smooth when holding a steady throttle. it seems to "surge" if that makes any sense. anyone know what's going on? :)


When is the last time you cleaned the carb?

  • grayracer513

Posted January 31, 2009 - 08:47 AM

#4

How far open is the throttle during the surging?

  • Boise93

Posted January 31, 2009 - 09:54 AM

#5

My 08 does the exact same thing as you describe. When I have my throttle open about 1/8 and a little below, it has a surging feel. My jetting is spot on and the bike runs great, starts on the first kick, and has no bog. I figure it's a race bike and not meant to run at 1/8 throttle. Anything higher than that and it runs like a bat out of hell. I just got used to it. I'm sure gray will have a fix if there is one though. He knows all and is a god in this forum IMO. I think he must've worked for Yamaha in a previous life.

  • 642MX

Posted January 31, 2009 - 10:12 AM

#6

I'm sure gray will have a fix if there is one though. He knows all and is a god in this forum IMO. I think he must've worked for Yamaha in a previous life.


Are you kidding?.... I taught Gray everything he knows.... :lol: :lol: :lol: :)

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted January 31, 2009 - 04:15 PM

#7

On the '08, use an NFPP needle. It has a smaller diameter straight section, and will richen the mix slightly at 1/8-1/4 throttle, which should help your symptoms and improve off-idle throttle response.

If the '07 is surging at 1/8-1/4 throttle, try either an NFLQ or NFLP needle (1 and two steps richer respectively)

  • bluebreadtruck

Posted January 31, 2009 - 08:58 PM

#8

YEAH, I think its a symptom of a lean condition. I had my bike jetted perfectly in the summer, now when I take it out around freezing i get a surge.

  • grayracer513

Posted January 31, 2009 - 09:53 PM

#9

Cold weather = dense air. Go richer to compensate, or put up with it until it warms back up.

  • Whyzee429

Posted February 01, 2009 - 04:05 PM

#10

i don't notice it when on the track. I notice it if i'm drying it off down the street or cruising down a fire road. it's most noticeable at 1/4 throttle openings I would say

  • Whyzee429

Posted February 01, 2009 - 04:07 PM

#11

i wouldn't say the weather has been freezing (30's), but maybe in the 50-60's. The bike just received a new top end and the carb WAS cleaned out. valves in spec also.

  • Boise93

Posted February 01, 2009 - 04:57 PM

#12

Exactly, but mine does it at 1/8 throttle. Misery loves company!





Related Content

Forums
Photo

First Hare scramble tips by dhend8


Dirt Bike   General Dirt Bike Forums   General Dirt Bike Discussion
  • Hot  33 replies
Forums
Photo

Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride


Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

Snake pit oct 30th by The Anvil


Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies
 
x

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.