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Discussion Starter #1
Before I jusr jump into a device that I know little about, I’m not ashamed to ask for help.

My carb is dripping fuel from the drain at the bottom of the bowl. A pretty fast drip at that.


My first blush is a stuck float valve but don’t they usually get stuck closed and not open?

What is the sequence of things to check?
 

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They often stick open....that's one of the reasons you hear of people religiously turning the fuel petcock to OFF when it's going to be parked for more than a few minutes.

Any time a float (okay, needle valve) sticks open (more than likely a little piece of schmutz holding it open, rather than it 'sticking open'), always always always check and see if the cylinder is also full of gas, and check the oil as it may be full of gas that went past the rings. Check and remedy those 2 things as well before trying to start it.
 

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First, shut off the gas and remove the drain screw and look to see if the tip is buggered (easiest things first!). If not, take the float bowl off and use some canned air to get into the needle valve and see if that fixes it. You can easily test with the bowl off. If that isn't it you will have to remove the float and the seat. Look at this: http://tw200forum.com/forum/technical-write-ups/881-tk-carb-photos-parts-identification.html
Photo 11.

And this for the delicate job of float removal: http://tw200forum.com/forum/technical-write-ups/967-removing-carburetor-float.html

While you are at it, replace the bowl screws (JIS!!!) with SS Allen screws so it's much easier next time.
 

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If the drain at the bottom of the carb is leaking, the drain screw is not sealing. As it leaks the carb float falls and the carb refills. When the lower drain is closed it shouldn’t leak no matter how full the carb is. Do as Rocky suggests and remove the bowl and check the drain screw for debris or damage. Replace for less then $4.00 on-line at boats.net. You can replace those bowl screws with Allen’s while you’re at it. Mine used to leak as well. This fixed it.
 

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Discussion Starter #6
Great suggestions and the links to the older posts showing float removal are really helpful.

Still, while I’m not usually timid, don’t think I’m ready yet to attemp a carbectomy...
 

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....... When the lower drain is closed it shouldn’t leak no matter how full the carb is........
Don't mean to be rude but this is not always true.

The bowl overflow tube also drains from that same opening at the bottom of the float bowl.




The leak from the overflow tube can be caused by an open float valve or a leaking o-ring on the float valve seat.


Here is a leak caused by a bad o-ring:



Here was the problem:




Even if the float valve is closed, fuel can seep through the faulty o-ring and around the valve seat causing the bowl to overflow.

Turning off the petcock when the engine is stopped can stop the leak, but doesn't cure the problem.

Depending on how severe the leak is, a running engine will burn more fuel than will leak past the valve seat..... but having fuel dripping on a hot engine is never a good idea.


jb
 

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Jb, no harm no foul. ?
Mine was leaking there and after cleaning it it stopped. It’s been a while and I forgot about the little snorkel tube sticking up from the bottom of the bowl. My bad.
 

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also make sure the float doesn't have a hole in it and hasn't filled with fuel which would cause the bowl to fill with fuel
 

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Discussion Starter #12
Any time a float (okay, needle valve) sticks open (more than likely a little piece of schmutz holding it open, rather than it 'sticking open'), always always always check and see if the cylinder is also full of gas, and check the oil as it may be full of gas that went past the rings. Check and remedy those 2 things as well before trying to start it.
Never would have thoughjt to do that!

So, how would I check for gas in the oil? There's no dipstick and can't really see gas through the sight glass...
 

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Discussion Starter #14
You can smell it at the oil cap when open.
I removed the oil fill cap, took a big whiff and breathed a sigh of relief. No fuel smell.

But, the drip from the drain is worse now; a steady drip.

Gotta do something soon!
 

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Is this the first time you’ve had gas in the carb? Or had it been drip free in the past.

Like Rocky said, check the easiest things first. Removing the drain screw does not require carbectomy. It’s easy unless the head is rounded. Just make sure you have the drain tube in some kind of collection bin (gas can). That screw is $5.50 from Bike Bandit if it looks like it’s shabby. Check out jbfla’s pics To see what a good one is supposed to look like. Cheers
 

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Discussion Starter #16
Is this the first time you’ve had gas in the carb? Or had it been drip free in the past.

Like Rocky said, check the easiest things first. Removing the drain screw does not require carbectomy. It’s easy unless the head is rounded. Just make sure you have the drain tube in some kind of collection bin (gas can). That screw is $5.50 from Bike Bandit if it looks like it’s shabby. Check out jbfla’s pics To see what a good one is supposed to look like. Cheers
Not the first time its had gas but perhaps I just didn't notice it until now?

Without trying too hard so as not to round the head of the drain screw, I couldn't get it out. I'll try again tomorrow with a better phillips head screwdriver.
 

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Don’t use Phillips screw drivers most are JIS head screws. it stands for Japanese Industrial Standard they are different than Phillips. Use the screw driver from the tool kit it IS JIS.

That drain screw seems to get stuck easy. I just had to replace one that striped out even using a JIS screw driver. I think that is why the replacement comes with a spring and o ring like the pilot jet screw. You only need to seat it gently the spring keeps it from backing out.

Not the first time its had gas but perhaps I just didn't notice it until now?

Without trying too hard so as not to round the head of the drain screw, I couldn't get it out. I'll try again tomorrow with a better phillips head screwdriver.
 

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Discussion Starter #19
Don’t use Phillips screw drivers most are JIS head screws. it stands for Japanese Industrial Standard they are different than Phillips. Use the screw driver from the tool kit it IS JIS.
Never heard of that...

Thanks, Tweaker.
 

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Discussion Starter #20
Well, even with the included JIS screwdriver, I can’t remove the drain screw.

It seems to be a combination of rounded slot and too damn tight!

Any suggestions appreciated.
 
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