Won't take fuel

[ovhonda1]

So I put a 38 mm carb on my 86 R. Gas flows out of the petcock freely. Carb will not take fuel. It stays in the tube wanting to go into the carb but it won't let it in. There is an air bubble in the line as well that I cannot get out. Anybody run in to this before? I have cleaned the carb thoroughly as well, including the fuel passage.

[swampthang]

Sounds like you need to adjust your float height.

[kasey200x]

First you should check the float. If possible(even if you have to remove from the engine) pull the bowl off of the carb. Hook up the fuel line to the carb, and hold the carb the way it would be positioned on the bike, then operate the float(moving up and down) and see if it allows fuel through.

Good luck

[yamaha driver]

try opening the drain plug on the bottom and tapping the bowl with a plastic screw driver to make sure they are not stuck

[ovhonda1]

I opened the drain at the bottom of the carb and nothing. Not a drop. Even if the float is not adjusted correctly, wouldn't fuel still be in the bowl? I am going to take carb off again and clean everything again, set the float correctly and see what happens. I will also try to hook up while apart as suggested before putting back on as well. Keep you posted. Thanks for the replies.

[atc007]

Pretty simple. You have a blockage from the fuel nipple to the float needle. Either the needle is stuck/glued,,or,there is a wasp nest or something in the inlet. HIGH compressed air will clear it,,then worry about your float and needle.

[yamaha driver]

if you use high compressed air make SURE to blow it threw the seat part instead of the inlet

[kasey200x]

If the float adjustment(the little tab where the float touches the needle) is bent all the way up it could cause the needle to stay seated.

The best way to find the location of your problem would be to remove the bowl, float, and needle. Then see if you can blow through the fuel line, or attach the fuel line to the tank normally and try to run gas through it.

If it flows easily with the needle taken out, you know that is the problem(float adjustment/dirty needle valve). If it will not, then the passage between the fuel inlet and the needle is clogged.

[tri again]

Stuck float needle?
I usually blow into the fuel line and turn the carbs over to see if the air blow thru and stops
when the carb is upside down before I put them back on.

I've also gotten aggravated after a carb rebuild and just mouth blow some mystery oil
into the fuel inlet with the carb drain open.
Beats taking them back off. esp es or sx

ALSO had a few of those see thru paper element gas filters that honestly would NOT let fuel
through with simple gravity but you could blow through them with no resistance.

[RaceBannon]

Had the same situation with one of my '85 SX's. After painstakingly rebuilding the carb and cleaning the inside of the tank of a new acquisition, I reassembled everything including new fuel line and inline filter. Put gas in it attempted to fire it up-nothing-no gas entering the filter. Opened the bowl drain hoping to get it to flow again-nothing. I opened the tank (leaving the bowl drain open) inhaled deeply and blew into the tank. The filter filled, gas began to flow from the drain, I closed the drain pushed the start button and it's been starting and running without issue eversince. Good luck.

[thestud25]

I had this problem yesterday. I will about guarantee that your float level is off as most are suggesting. If you loosened the bolt on the bottom of the carb and no gas came out it makes even more sense that the float level is off or the needle is stuck.

[Dirtcrasher]

Simple, just take the carb off, take the bowl off, blow into where the gas in and see if it changes when the raised or lowed.

And, if the float adjustable portion is bent up" Then I imagine it is holding the fuel back prior to it getting past the needle.