Sooty spark plug



4 replies to this topic
  • johnhab

Posted January 03, 2002 - 03:59 PM

#1

Maybe someone can give me advice about my 2001 YZ426. I had it start missing and popping this summer after riding it for four months. It always starts and idles fine and will run fine for a couple of weeks before the plug goes bad and needs to be changed. It doesn't seam to be a jetting problem because it runs to well, and I follow the YZF rules of not turning the throttle when starting and letting the air filter sit for a couple of days after oiling before riding. I went to a CR7E and this helped but it still doesn't last long enough. I sometime take off to quick after starting and I think this is part of my problem maybe the bike is to cold to burn off excessive fuel.

  • sirthumpalot

Posted January 03, 2002 - 05:24 PM

#2

Different bikes seem to have different solutions when it comes to fouled spark plugs, but for me and my '01 the answer was changing brands of gas. I was fouling one almost every time I started it while it was cold (first start of the day). I changed brands of gas and with no other changes at all I have not fouled a single plug since.

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

Posted January 04, 2002 - 02:36 AM

#3

On my 01, the best thing I did was to start running a 50-50 mix of VP 108 octane and 92 octane pump gas and did the BK mod. Starts first kick EVERY TIME and have been on the same plug for 3 months now!

  • mikeolichney

Posted January 04, 2002 - 09:05 AM

#4

These guys are right, the gas can cause this problem. The ethanol in the gas (madated near Denver in the winter) will foul my bike right away with a CR8E plug. A CR7E plug won't foul right away, but it sputters and runs poorly. Do not use gas with ethanol in it!

  • Merfman

Posted January 04, 2002 - 10:33 PM

#5

Same story, different verse. A buddy of mine was having troubles with his '01 after the weather has turned chilly. Couple of weekends ago he decided to try 112 race gas and a 1 step leaner main jet. He reported a nice tan plug at the end of the day.

(Mike O, I tried to email you this but you might never have gotten it)

Merf





Related Content

Forums
Photo

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies
Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo

First Hare scramble tips by dhend8


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

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 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.