# A carb mystery...need help!!!



## 666K9 (Jul 10, 2006)

Am hoping someone can help with this...

I have a Toro Recycler push mower with a Kawasaki FC150V. The carb got gummed and dirty so I took it apart, cleaned it up, and put it back on. It kept surging after the cleaning so I ultimately decided to get a new carb because the mower was in good shape. One thing I noticed before putting on the new carb though was that no matter what I did, fuel kept coming up through the main nozzle into the thoat of the carb. This is happening while nothing is being done to the mower...simply opening the fuel shutoff valve at the gas tank and watching the overflow. I decided that the float needle and/or seat was bad and the problem would be fixed with the new carb. It still does the same thing with a new carb.... I've completely flushed the fuel tank for any debris, changed the filter and fuel line, and cleaned the float needle and seat. I dry it all up and don't mess with anything other than to turn on the fuel and just watch. As the fuel fills the bowl, it bubbles up the main nozzle into the carb throat until the bowl is full. I dry up the throat area, don't tip the mower in any direction, and it will start and run fine. But when I shut it off and let it sit for awhile, it floods the carb and when you try to start it, gas gets pushed out of the muffler....HELP!! If the float needle and seat are clean...and it's a new carb....how is the fuel overflowing into the throat of the carb??????


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## 30yearTech (Sep 14, 2006)

Try it without the fuel cap on the gas tank and see if it still leaks out, If it does then there could be a problem with the float bowl vent. Some carburetors vent out of the air filter and or carburetor insulator and the vent could be blocked.

Post your model and serial number off of your mower and I may be able to tell how the carburetor vents. If it stops leaking when there is no fuel cap then your cap may not be venting the tank, clean the cap or replace it if needed.


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## 666K9 (Jul 10, 2006)

Thanks for the reply Tech. The mower is a Model: 20044 Name: SR-210S S/N: 9900136 Am heading out know to try what you suggested. Thanks, again.


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## 30yearTech (Sep 14, 2006)

Looks like your carburetor vents out of the top, there should be a nipple on the top of the carburetor that a short piece of hose attaches too. Make sure the hose is open all the way through and not plugged up with any debris, a plugged bowl vent will cause carburetors to flood.

Good Luck...


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## paulsi (Nov 21, 2007)

I had the same type of problem with a B&S engine carb. I just concentrated on the needle, seat and float. Eventually I got it fixed. I took the carb out, put the seat in correctly, attached a piece of tube to where the fuel line goes in. Without the bowl in place, I filled up a cup with water and and lowerd the carb and started blowing air into the tube; Kept adjusting the seat until the float could easily seal the inlet while lowering it in the cup full of water. Final it happened, I put the carb back and with a full tank of fuel, the mower has not leaked a drop for the last 12 hours.I will keep my fingers crossed. 
Along with other suggestions given by good folks as above, also consider what I did. The major mechanism of stopping the fuel from oveflowing is the inlet needle, seat and float.

Paul


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## 666K9 (Jul 10, 2006)

Tech, I think you nailed it (got my fingers crossed). Watched it without the gas cap and it didn't overflow. Put the cap on and it still didn't. The vent tube coming off the vent nipple was stuck onto the limiter cap so I pulled it off and let it hang. Just to be on the safe side, cleaned the gas cap up also and it seems to be holding...runs like a champ. Thank you. 

Paulsi, thanks for the reply.


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## 30yearTech (Sep 14, 2006)

666K9 said:


> Tech, I think you nailed it (got my fingers crossed). Watched it without the gas cap and it didn't overflow. Put the cap on and it still didn't. The vent tube coming off the vent nipple was stuck onto the limiter cap so I pulled it off and let it hang. Just to be on the safe side, cleaned the gas cap up also and it seems to be holding...runs like a champ. Thank you.
> 
> Paulsi, thanks for the reply.


If the vent tube end was plugged into the limiter cap then that was the problem on the new carburetor. If the float bowl does not vent, then as fuel flows into the bowl pressure builds up in the bowl, this pressure can actually hold the float down and keep it from stopping the fuel flow. It should be alright now.
:thumbsup:


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