lt80 keeps flooding

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Mar 21, 2016 | 02:07 PM

#11

ronhat

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Joined: Mar 2016

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Quote:

Originally Posted by vpracer

I have been searching for a thread that would help me too. But mine situation is slightly different
Issue: Once I get the LT80 running it has gas dripping out the air intake. I realize that I have a flood condition but I have cleaned the carb no less than 8 times and rebuilt the carb with a new float valve and seat. I have also changed out the petcock to remove the vacuum line.
I have run the carb out of fuel by shutting off the petcock.
I have run the carb with the choke open and with it closed and it still is dripping fuel while running.
Stock jets in the entire carb.
Here is what I have not done
I have not tested the floats to see if they are leaking, I didn't see any evidence of residue inside the floats.
I have not plugged the vacuum line from the carb.

I am getting to the end of my rope and I could use some help
Thanks

The fuel tank valve is a shut off valve that is operated by vacuum from the engine. There should be no fuel coming from the fuel tank if engine is not running. The fuel line goes straight into the carburetor until bowl is full and float closes metal valve preventing more fuel entering carburetor. It could be that your fuel tank valve is not shutting off the fuel. And also your float valve is bad. This will allow gas to fill up your crankcase via your carburetor when the atv engine is NOT running because neither the fuel tank valve nor the carburetor float valve is stopping fuel flow from fuel tank. However, I do not think fuel would drip from the air intake when the atv engine is running as air is being sucked into the carburetor as it would suck that fuel into the carburetor/engine. And if any fuel at all is coming out of the carb air intake, that means your crankcase is flooded with gasoline. You should place your fuel tank valve in the on position, remove the fuel line at tank and see if any fuel is running out.

Mar 23, 2016 | 08:29 AM

#12

LT80

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I've seen the petcock go bad and leak fuel down the vaccum hose.

Mar 23, 2016 | 10:47 AM

#13

ronhat

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As a fellow just mentioned, the fuel tank vaccuum operated valve could indeed go bad. It contains a rubber diaphram which could rupture and that would allow fuel to be sucked straight into the carburetor via the vacuum line.

Mar 24, 2016 | 03:09 AM

#14

merryman

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Joined: Oct 2013

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From: Lancaster England

All of a sudden LT80 petcocks have started to appear on UK eBay at about £6, direct from China. Anybody tried one yet?

Jul 23, 2016 | 02:58 PM

#15

atomic44

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Great thread guys. So where is the vacuum line on the carb you suggested plugging? Is that only if you swap to the inline shutoff mentioned above?

Jul 29, 2016 | 09:38 AM

#16

410Customs

Off Road Builderaholic

Joined: Jul 2016

Posts: 150

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From: Crawlorado

Install Yamaha Banshee petcock in fuel tank. It bolts directly in
Plug the vacuum line that used to run from carb to petcock

Check operation of floats in carb
Even with a faulty petcock the floats should shut off the fuel flow when fuel reaches the top of the fuel bowl.
So excessive fuel in intake, running waaaaay too rich can often be the floats sticking/improper float level

On these carb,s underneath the float needle valve there is a brass piece. it must be pulled from the carb (Plyers) and cleaned as well as the orifice it sits in