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Discussion Starter #1
I'm trying to get a better understanding how the carb works on my 660. Are there diagrams or videos? I want to understand why my carb only leaks when I turn my fuel on after storage. When I start the grizz it stops and won't leak anymore. After I'm done I always run gas out of carb.
 

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There are multiple reasons why a carb overflows. You should remove and clean your carburetor, Look closely at your needle valve and seat. the seat also has a o ring that can leak.You can see this o ring when the seat is removed.
 

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Outlaw41- Here we go: gas on and the gas flows into the float bowl via the needle and seat. Once the float's reaches the level it is set for the needle and seat turn the flow of gas off. If the level of the floats are to high ( or the needle and seat and not working properly) the fuel raises high enough to go into the overflow tube which then flows out of the tubing on to the ground. There is also a (not all the time) rubber O-ring that helps seal the needle & seat inside the seat of the carb. That internal seat must be clean and not have pits in them. If it did then the gas will get by via the seat not being clean or the O-ring not sealing. Generally if the floats stick the fuel just pours out of the overflow tube. If the floats have any liquid (holes in floats) then the floats are heavy and will stay in the down position and let fuel continually flow. When your riding the floats continually move up and down depending on throttle position. Wide open float level drops and fuel keeps going into float bowl. throttle off and then the float will raise and shut off fuel flow to the float bowl. Works just like your toilet bowl flush it and water comes in to the level it's set at and then stops. If it didn't stop then water will continue to run or leak. To me if it's dripping then something is not seating properly. If it just flows then the float is stuck in the open position. Normally it's the needle valve & seat. If it's dripping it can be the O-ring, dirt, bad seat or even a small hole in the float causing it to drop and open just a little bit causing it to overflow. When you turn the petcock off fuel can no longer flow into the bowl, hence it stops leaking. The reason the Grizz will run for a little bit after you turn it off is because it's using whatever fuel is left in the bottom of the float bowl. Once that's depleted the engine dies due to no more fuel available. Hope this helps.
 

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Outlaw41- This may help:



 

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Discussion Starter #6
I appreciate the help. I'm starting to understand a bit better. I'm trying to visually see what's causing my leak since I just did a rebuild. Seems odd to me it only leaks after I turn fuel on. After starting it's fine. And if I stop it and leave fuel on it doesn't leak.
 

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Discussion Starter #7

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Outlaw41- one more:
 

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Now that your completely bored watch this for the needle seat cleaning:
 

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Outlaw, so is it safe to say that it only leaks when cold? Once the carb warms up from riding then I doesn't leak? If that's the case, I would say it's a hardened o-ring that swells up when it gets warm from the engine heat.
 

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Discussion Starter #11
Outlaw, so is it safe to say that it only leaks when cold? Once the carb warms up from riding then I doesn't leak? If that's the case, I would say it's a hardened o-ring that swells up when it gets warm from the engine heat.
Say I'm done for the day. I put it in garage turn the fuel off and run it out the gas. It sits for a day or 2. I'll turn petcock on and it starts to drip. I turn on engine and it stops leaking and won't leak anymore.
When I was hunting I wouldn't drain carb when it sat. And it wouldn't leak. Only leaks when gas is first turned on.

There is no gas in air box and non in oil
 

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Discussion Starter #12
Starting to think it has something to do with the float level
 

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this is a classic float issue. no doubt about it. my guess would be you have something going on with your float valve/needle. either a piece of dirt in there that isnt allowing it to seal, or it is old and hardened and not getting a good seal. there is also a chance that your float needs to be adjusted, but i doubt it.

99% of the float valve issues i see only happen when it isnt running. the amount it leaks is less than the engine uses, so when it is running, it doesnt overflow. but when you stop it, it will drip. cold or hot has nothing to do with it. i would imagine if you didnt run it dry after using it, it would start leaking shortly after you turn off the machine.

easy fix. 90% of the work is getting the carb off the machine and onto the bench. get some carb cleaner, and a rebuild kit. all you really need out of it is the float valve and the bowl gasket, but id replace and clean everything else i can get to easily. id skip anything that is part of an adjustment.
 

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Discussion Starter #14
Idiggplants- I just rebuilt the carb about a month ago cause of the drip. I replaced float needle & seat, cleaned ext. It worked good with no drip for about 2 weeks now it's back at it
 

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and to refer to the first video that wgc posted... your issue is in that first step... where it shows the fuel enter the bowl and the floater raise the float valve to stop the flow of fuel... something in that process is not right. either the valve isnt getting a good seal(most common), or the floater is improperly adjusted so when the fuel is at the proper level, it isnt pushing the float valve up high enough to stop the flow. one thing that video doesnt show is the overflow in the carb. when and if the fuel level gets too high in the bowl, there is an overflow that lets the excess fuel out. if it wasnt for that overflow, the fuel would fill up the whole carb and drain into your cylinder. causing 2 dangers. 1, it will make its way past your piston rings and into the oil, ruining your oil viscosity and thus ruining your engine.. or 2. hydro-locking your cylinder, and thus ruining your engine.
 

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From another thread he has already replaced the needle/ valve and O-ring.
 

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Discussion Starter #17
I appreciate everyone's help. I apologize if I'm causing confusion. I just really wanna understand the carb properly before I tear into it again. The inner part of petcock dos look crusty but I do have an inline fuel filter about an inch from carb inlet
 

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Idiggplants- I just rebuilt the carb about a month ago cause of the drip. I replaced float needle & seat, cleaned ext. It worked good with no drip for about 2 weeks now it's back at it
ok, there is a good chance that you got the piece of dirt or whatever out of there, but a new piece has gotten in there. id say that you might want to drain the gas tank and use some fresh gas, or possibly check your fuel filter, if equipped. not familiar with the 660s, but sometimes there is a screen built into the petcock. if that is all that is on there, id personally install an inline one between the tank and the carb...

regardless of if you just replaced them, the issue is still with one of those 2 items. float valve, or float. there is really nothing else it could be. id still be leaning towards dirt in the valve. if the float was improperly adjusted, it wouldnt have stopped at all. the question now, is... what is causing gunk to get in your carb and mess with the valve seal?

just to make sure... this leak is coming from the overflow tube, right... not seeping out of the carb somewhere else?
 

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I appreciate everyone's help. I apologize if I'm causing confusion. I just really wanna understand the carb properly before I tear into it again. The inner part of petcock dos look crusty but I do have an inline fuel filter about an inch from carb inlet
ha. your answering my questions before i can ask them.

if the filter is old, replace it. they are cheap. id recommend emptying your gas tank as well. make sure there is no silt or rust at the bottom of it.

clean that bowl out real good again. clean the valve off, and shoot some cab cleaner up into where that valve sits. then see what happens.
 

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Discussion Starter #20
ha. your answering my questions before i can ask them.

if the filter is old, replace it. they are cheap. id recommend emptying your gas tank as well. make sure there is no silt or rust at the bottom of it.

clean that bowl out real good again. clean the valve off, and shoot some cab cleaner up into where that valve sits. then see what happens.
I noticed that!!lol. On one of this vids WGC posted it showed a guy using a drill and que tips with brass polish. Looked to work really well! Gonna have to try that.

When I did the rebuild I did touch anything that adjusted including float level. Thanks for all the help & input
 
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