View Full Version : More carb issues

04-13-2009, 01:26 PM
Hello all,

I am having problems with the carb on my 86 350X motor. It leaks out of the overflow. I have put a carb kit into it and it is still doing it. When I initially fired it up, I blew some air through the inlet without the float on it and it blew some stuff out of it (looked like black rubber). Now the float valve dont seem to want to close and stop the flow of fuel.

Anyone got any ideas?



04-13-2009, 01:38 PM
Hey Dan,

did you replace the needle and seat, or just replaced the gaskets etc?

Did the float or any of the parts get bent in the rebuild process?

Pull that sucker back off, remove the float bowl and investigate if you have proper action and movement in there. Check that needle making sure there is no debris obstructing it from closing. Let us know what you find.

04-13-2009, 03:33 PM
Make sure you don't have a "sunk" float as well . The black "plastic" ones will absorb fuel over time and become heavy - the brass ones sometimes will wear a hole and fill with fuel . Needle , seat and float are the most delicate parts of the carb . At any rate , i'd pull it off

04-13-2009, 04:02 PM
I have had it off and it dont have any gunk in it. As far as I can tell there is not a way to take the seat out of the carb. The float is clear plastic and looks ok, but does not adjust like the old ones did.



04-13-2009, 04:19 PM
I had an 1991 Yamaha FZR 600 back in the day when I lived in Okinawa. I had a carb that kept dumping fuel and could not figure out what the heck was the matter with it. Anyhow, I ended up throwing a rebuild kit at it and didn't replace the needle. Slapped that unit back on the bike. That carb kept dumping like a big dog. Ended up taking it back off and replacing the needle, sure enough it was fixed. Upon closer inspection of that needle there was a microscopic crack that was preventing it from sealing and stopping the fuel.

Anyhow, how is the movement of the float and needle? Hold the carb upright and see if it seems to be able to move freely and close the flow?

Basically, the way I see it is your needle is not closing the hole for some reason.

My guesses:

The needle is cracked or obstructed
The float has a hole and is a submarine
There is not enough movement in the mechanism (whether its bent or something is obstructing its movement).

Hold the card upright with the bowl removed and fiddle with it. See if the float moves freely. Remove the needle and inspect it well. If there is nothing obvious, bench test it. Plug in the fuel line and manually push the float closed, see if it works properly. If you are manually holding the float up and seating the needle and there is no flow coming in, then you know there is something obstructing that unit and preventing in from moving/closing all the way.

I hope all this makes sense. I have been IT Processing all day. All my words are starting to look like nuts and bolts in a spare parts bin!

04-13-2009, 09:36 PM
one way to check is take the carb and pull the bowl of then hook the gas line on and turn the gas on and push the float up adn the gas should shut off if it doesnt then you no its probably a needle n seat problem

04-14-2009, 04:16 PM
I think that I may know whats happening. I have the motor set leaning back a bit. The carb is not level. Me thinks that the bowl is not filling right. It will be a lot of work to change the motor angle, but I may have to do it. I have rotated the piece between the carb and the motor, but that did not help. I may try cutting the top end of the carb side to see if I can square it up a bit. They are cheap on ebay if I mess it up too bad.

Thanks guys, this board is great!!!!


04-14-2009, 04:55 PM
Did you try to bench test that carb at the same angle it sits on the engine?