WR400 goes wide open throttle upon startup.
Posted July 23, 2014 - 12:08 PM
Posted July 23, 2014 - 12:27 PM
Posted July 23, 2014 - 01:01 PM
Posted July 23, 2014 - 01:14 PM
Posted July 23, 2014 - 01:35 PM
Posted July 23, 2014 - 03:20 PM
If you start with a high idle, then set your fuel screw, you will have a problem
Must start with the lowest possible idle first, then turn the fuel screw for max idle.
If it goes to high, start over with a lower idle
Posted July 24, 2014 - 10:39 AM
Does that bike have a hot start lever? I had mine get in a bind and it stuck open. High idle, popping on decal, no amount of idle adjustment did anything.
I don't think the older 400's had hot start levers, but thought it was worth mentioning.
Also, check for vacuum leaks in the hoses.
Posted July 24, 2014 - 12:14 PM
If it is original, check the parts. If it's aftermarket pull and put in original to see if there is a difference.
Posted August 22, 2014 - 05:53 AM
Sounds like you might have an intake air leak. Check both rubber boots on either side of carb, but that usually does not cause red line....usually more like high and/or inconsistent idle.
Check your throttle cable routing, this could be it especially if it worked for awhile then went haywire.
Also I have seen where a broken or cut o-ring on the fuel screw can cause all sorts of idle issues, but there again NOT to red line.
Popping on decel can also be caused by a bad seal on the exhaust donut.
Posted August 22, 2014 - 11:27 AM