carb overfilling.

marc-andre hubert · Joined: 10 Apr 2012 Posts: 181

can't figure it out.. i clean everything i start it no fuel filling up on bottom of overfill tube on carb bowl cover, then out of nowhere it will overfill and well overfill and foul plugs

if i blow on fuel feed line into carb and hold floats at 90degree no air goes thru so no fuel should go in and overflow it? needle seat and needle are perfect. this is keihin cr125 no pump around, runs awesome 90% time..

any idea

Brian Degulis · Posted: Mon Feb 18, 2013 6:11 am Post subject:

Marc the fuel pump pressure is poping the the float needle. It's a common problem that happens because the carb is designed for gravity feed and we use pumps. There's a lot of posts on it and solutions try a search.

Brian

Todd Kageals · Joined: 15 Jun 2012 Posts: 271

Marc,

Try adjusting the floats. My brand new PWK was doing this with my Dellorto fuel pump. I adjusted the floats about 1 mm and all is well now. Of course....you could just get it converted to pump around.

Todd

marc-andre hubert · Joined: 10 Apr 2012 Posts: 181

thanks will reduce pressure first, since i have gone thru the floats a few time, and when its upside down at 90degree no air goes thru so fuel is being shut down at the rigth level,

on a side note, i went and tapped on side of carb gently and started it and everything is perfect. maybe needle got stuck open.. but will where i have the Y coming off the fuel pump i will now have 1 line direct from pump to carb and other direct back to tank. should not hurt anyway

Jeff DeMello · Posted: Mon Feb 18, 2013 12:00 pm Post subject:

Try Todd's suggestion first...
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Jeff DeMello
Emmick F125 Pavesi

marc-andre hubert · Joined: 10 Apr 2012 Posts: 181

unless i got wrong info, i already adjusted, maybe im doing it wrong? but karts hauls and runs a1 then out of the blue it will overfill? if it was the floats it would overfill right away no?

Tyson Henry · Posted: Mon Feb 18, 2013 12:13 pm Post subject:

Jeff DeMello · Posted: Mon Feb 18, 2013 12:14 pm Post subject:

Check the needle and seat and make sure it is clean.. Do yo filter your fuel?? It sounds like your needle is sticking from debree in the fuel.
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Jeff DeMello
Emmick F125 Pavesi

marc-andre hubert · Joined: 10 Apr 2012 Posts: 181

only have filter from tank to pump not pump to carb. will add one now,

also when you say raising the floats it means pushing them up higher in the body not down into the bowl right.

Jeff DeMello · Posted: Mon Feb 18, 2013 12:33 pm Post subject:

Float lower into the bowl. You want less fuel in bowl.
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Jeff DeMello
Emmick F125 Pavesi

Tyson Henry · Posted: Mon Feb 18, 2013 12:34 pm Post subject:

Jeff DeMello · Posted: Mon Feb 18, 2013 12:37 pm Post subject:

Don't add another filter. The one you have is good enough.
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Jeff DeMello
Emmick F125 Pavesi

marc-andre hubert · Joined: 10 Apr 2012 Posts: 181

thanks guys you all have been very helpfull, off to work and lapping this sat for results.

Josh Michalosky · Advertiser Joined: 01 Oct 2007 Posts: 87

We usually put a T in the fuel line between the carb and the pump, then run it back to the tank as a pressure release.
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Josh Michalosky
Accelerationkarting.com
1-888-466-KART
sales@accelerationkarting.com

marc-andre hubert · Joined: 10 Apr 2012 Posts: 181

yeah i have that.

fuel pump to Y then T at the carb one to carb the other back to tank, and of course i have the other return going straight to tank