Kohler Courage 20 / SV600 Walbro 3 carburetor leaking from float valve
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Not necessarily as it can to a point that cause flooding at off load engine speeds. Besides shut-off valve is only a band aid approach to the problem. They are find for problem of seepage overnight and transportation induced porblems. I have seen needle seats to etched and even brand new needle valves will still leak. Now if you have a six point countersink bit of the right and angle the seat can be cleaned but if it leaking around the outside sealing surface nothing will be a permanent fix except replacement.
Gord Baker
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Get some carb cleaner and carefully wipe off the Viton tip of the needle.
It does not require a Viton 'seat'. Clean the bore where the needle goes.
Looks like Ethanol contamination to me. Set float as described above. When you turn the key Off/On there should be an audible 'click'. Hold your hand on the shut off solenoid and you should be able to feel it working.
It does not require a Viton 'seat'. Clean the bore where the needle goes.
Looks like Ethanol contamination to me. Set float as described above. When you turn the key Off/On there should be an audible 'click'. Hold your hand on the shut off solenoid and you should be able to feel it working.
I’ve found that extra fine lapping compound and Q-tip works to clean up seats. I don’t know why brass compound would not work. If you try it make sure you clean the carb at least twice or you may end up with compound in the cylinder. I’ve also found that if you invert the carb, with float and needle install, and blow very hard with your mouth, you will blow you cheeks out before the float moves and opens the seat. Old fart job site trick.
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Yet this will not find low leakage rates which why I invert and use 5-10 Psi (usually close to pop off pressure the better) by applying using a pressure pump and checking after 30 minutes of standing pressure to see if any leakage is detectable. A positive seal will not leak any. Rivets only massive leakage can be found using your method Rivets. I have even submerge carburetor to check for leakage.
Using fine valve grounding compound only works to clean up a dirty seat but not a badly pitted or etched one. That require countersinking (must use the correct countersink bit) or repacement if it is the seat to seat contact area that is leaking but the seat is leaking around the contact area between the seat the carburetor then a new seat need to be installed.
Using fine valve grounding compound only works to clean up a dirty seat but not a badly pitted or etched one. That require countersinking (must use the correct countersink bit) or repacement if it is the seat to seat contact area that is leaking but the seat is leaking around the contact area between the seat the carburetor then a new seat need to be installed.
Maybe you can’t get these methods to work for you, but they have worked for me when I’ve had to resort to them in the field or to salvage a NLA carb. Maybe I’m the luckiest old fart tech around. Yes, I have lapping compound and Q-tips in my travel tool box.
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Or maybe you got heck set of lungs. I don't as Pneumonia took a lot that away. which why Covid would probably take me of this old mean world. It is like some people can smell gas in oil but I have never been able to do that either. I cant where carburetor with 8 psi of pressure is leaking down pass 7 psi without a gauge.
Now of course I work with the cubes and the larger carburetors.
Vic bellan
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your seat on the carb needs serious cleaning, and with a new needle should stop the gas flow when required!
You guys are all amazing! I don't think I can respond to everyone all at once 
Thank you for all the pointers. I bought some Permatex valve grinding compound and cleaned the seat; that q-tip baaaarely fit in there. I'm using the replacement needle as well.
So here are the results (so far anyway):
That's a bit fuzzy but you can actually see the shine off the brass in the valve seat now. I also used a dental pick to clean out the area around the opening and then hit everything with carb cleaner *a bunch* to try and make sure that none of the compound is still in there. It looked clean when I was done.
Here is the re-terminated end of the grounding wire attached to the carb body:
I mashed down on that ring terminal with my lineman's pliers and it crimped on there quite firmly. Looks a bit festive.
Also, here is the assembled float from the side; you can see that it is pretty much horizontal. It's a plastic piece and it seems like it's in decent shape so I don't think it's a part of the problem. We'll see
The float has the new needle attached to it, so hopefully that will help as well.
Then I mounted the whole thing back on the mower and secured it on the studs with the nuts that actually hold the back plate for the filter box. Reconnected fuel line as well.
The picture is actually cropped out, so it's a bit fuzzy. I put a little gas in it and left the garage about 15 minutes afterwards. I'll go check it again to see if it's sealed up! I hope so...
Fingers crossed! If that worked then I have to double check the throttle positions. I totally dorked around with the governor before I knew what I was doing (the throttle plate won't close at low throttle position because... governor duh...) I followed the advice in the service manual for resetting the governor but I may have to get that dialed in. I have an induction tachometer I can use to test the engine speed if things aren't working quite right. Just want to avoid an overspeed...
Anyway, more to come! Thanks again all
Thank you for all the pointers. I bought some Permatex valve grinding compound and cleaned the seat; that q-tip baaaarely fit in there. I'm using the replacement needle as well.So here are the results (so far anyway):
That's a bit fuzzy but you can actually see the shine off the brass in the valve seat now. I also used a dental pick to clean out the area around the opening and then hit everything with carb cleaner *a bunch* to try and make sure that none of the compound is still in there. It looked clean when I was done.
Here is the re-terminated end of the grounding wire attached to the carb body:
I mashed down on that ring terminal with my lineman's pliers and it crimped on there quite firmly. Looks a bit festive.
Also, here is the assembled float from the side; you can see that it is pretty much horizontal. It's a plastic piece and it seems like it's in decent shape so I don't think it's a part of the problem. We'll see
The float has the new needle attached to it, so hopefully that will help as well.
Then I mounted the whole thing back on the mower and secured it on the studs with the nuts that actually hold the back plate for the filter box. Reconnected fuel line as well.
The picture is actually cropped out, so it's a bit fuzzy. I put a little gas in it and left the garage about 15 minutes afterwards. I'll go check it again to see if it's sealed up! I hope so...
Fingers crossed! If that worked then I have to double check the throttle positions. I totally dorked around with the governor before I knew what I was doing (the throttle plate won't close at low throttle position because... governor duh...) I followed the advice in the service manual for resetting the governor but I may have to get that dialed in. I have an induction tachometer I can use to test the engine speed if things aren't working quite right. Just want to avoid an overspeed...
Anyway, more to come! Thanks again all
Good news so far! No leaks from the carb last night despite gas being in the mower. I cycled the fuel solenoid a couple times this morning and heard it click every time the ignition was put into "accessory" mode (or whatever the term for that is on a mower). No fuel leaking yet! I am going to let it sit a little longer and then try to fire up the mower this afternoon. I have some starting fluid so hopefully it will fire up and then run on its own for a little while