99 Yz400f Carb Issue


8 replies to this topic
  • PAWPAWB

Posted November 08, 2008 - 07:05 AM

#1

I have noticed gas dripping from bottom of carb when bike engine is running:banghead: why is this?

  • ryan2214

Posted November 08, 2008 - 07:54 AM

#2

Are you sure it is coming from the bottom of the carb, or is it running down from another area and dripping from the botom?

  • PAWPAWB

Posted November 08, 2008 - 08:16 AM

#3

Are you sure it is coming from the bottom of the carb, or is it running down from another area and dripping from the botom?

Not sure yet but now it drips when fuel is turned on.

  • ryan2214

Posted November 08, 2008 - 08:54 AM

#4

First you need to find out where it is leaking from:bonk:

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  • PAWPAWB

Posted November 08, 2008 - 03:18 PM

#5

Someone said float was stuck and gas is escaping out where overflow tube should be attached. if so how do I unstick the float?

  • ryan2214

Posted November 08, 2008 - 03:59 PM

#6

First, is there an overflow tube missing?

  • PAWPAWB

Posted November 08, 2008 - 04:30 PM

#7

Carb has very small post with opening that might have missing tube. This seems to be where gas coming from. post is on bottom of carb.

  • ryan2214

Posted November 08, 2008 - 05:14 PM

#8

There is one overflow tube thats on the botton left side of the carb. The other's (I beleive 4 additional) come out near the top of the carb. A while back my 400 was doing the same thing, and one day it just stopped. I beleive like you were saying earlier the float was probably stuck and it just freed it self. You can try LIGHTLY tapping the carb with a wrench or something similiar. If this deos'nt work you will need to take the carb apart and clean it out. By any means I am not a mechanic this is only advice. :worthy:

Ryan

  • grayracer513

Posted November 09, 2008 - 12:37 PM

#9

The small post you speak of is in fact missing a tube that is supposed to carry leaking fuel over the back of the engine and out below the bike.

The problem is that the float needle is not sealing, and therefore the level is getting too high, and running out the overflow. This can be because of a tiny (really tiny) bit of dirt on the needle/seat. Try running the engine with the gas turned off until it begins to stumble from lack of fuel, then turning the gas back on. Doing this will open the needle valve farther than normal, and the flood of incoming fuel may wash away the debris that's causing the problem. If not, try again, and then if not, you may have a repair on your hands.





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