fouling plugs

7 replies to this topic

Posted August 20, 2000 - 03:09 PM


my 99 wr400 keeps fouling plugs what is some jetting for western pa.....

  • Kevin_in_New_Hampshire

Posted August 20, 2000 - 06:13 PM


What are the stats on your bike, i.e. timing, exhaust, airbox, throttlestop?

  • Drehwurm

Posted August 20, 2000 - 10:14 PM



did you do any maintainance on the carb lately, changed anything else? Since when do you have this problem?


  • Taffy

Posted August 21, 2000 - 01:01 PM


while you're sorting out all your woe's, go to a softer plug. put a 7 in it. the trouble is, you can't sort your problems if you can't get it running first. right?

remember when you finally get it running sweet. this plug won't like hot days & lots of WOT for miles.

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Posted August 21, 2000 - 03:56 PM


the bike is stock only the baffle is out... as far as I know i just got it.....

  • MotoGreg

Posted August 21, 2000 - 04:59 PM


Clean your air filter...

Shut off the choke...

Just kidding :)

MotoGreg - The voice of absurdity
'99 WR400 - 'Cause thumpers rule and two-strokes drool!
'92 GSXR 7/11 (But I wanna get a dope 916)
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Posted August 22, 2000 - 12:46 PM


I clean my air filter every ride.........

  • Bill

Posted August 23, 2000 - 08:10 AM


The bike has a pumper carb. This means it has an accelerator pump in the carb just like a car. You cannot turn the throttle if the motor is not running. It will flood the bike and foul plugs.

You really need to provide details on when and how the plug fouls, under what conditions, temperatures, elevation. Your problem can be solved. It has been many times before on this web site. Just provide detailed info and wait for the responses.

So I would suggest you take the carb off and look at the pilot, main and needle jets. Also screw in the air screw in the bottom of the carb. Make sure you keep track of how many turns it is. Record what is being used and give more info as outlined above.

Oh and do not run the choke for more than 20 seconds. WR's don't like a rich condition for very long.


86TT225, 98CR80, 99WR, WR timing, throttle stop trimmed, air box lid removed, White Bros head pipe, silencer and air filter. Odometer and headlight removed. Moose hand and mud guards. YZ stock tank and IMS seat. Renthal Jimmy Button "highs" and Renthal Soft half waffle grips. AMA, SETRA.


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