Kawasaki fh680v RUNNING RICH!!! Stumped

slomo

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My symptoms also. I had bad fuel pump that filled crankcase with gas raising level of oil. Oil turned black and soot on plugs.
More like a bad carb needle and seat that was stuck open allowing fuel to get into the oil.

Bad fuel pump wouldn't push any fuel. Unless bad meant it pushed out 20psi and overwhelmed the needle.
 

dawgslife5436

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pulled the carb again and pressure tested it. good to go. didn't start leaking air until roughly 16 lbs. As to raisin1, I found the pipe (p/n 921917027) that goes from the bottom of the fuel pump to the left head was hard as a rock and loose. I do believe the oil smells like gas. As a matter of fact, when I checked it a few days ago it was above full a bit and I know I didn't over fill it. Even though the fuel pump is new. I'm going to change it and the pipe. Hopefully onto something. Thanks again for all the advise.
 

raisin1

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When fuel pump diaphragm ruptures fuel is sucked thru pulse tube which is under vacuum. Common problem. Sounds like your problem. About $11 on Amazon. New one wow! Don't know.
 

dawgslife5436

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Thanks again!!! I have a good used one I'm going swap from my back up mower while I wait for the new one to come in. I'll post the results. Once again, thanks for the input
 

dawgslife5436

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Changed the fuel pump with no improvement. Plugs fouled so bad in 20 minutes I couldn't cut anymore. Even though the OEM carb is fairly new, I'm going to disassemble and soak overnight. I already did this step minus the soak. Putting new spark in again for good measure. This one has me stumped.
 

bertsmobile1

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OK, time to get serious with this one
Please post the full specification number so I can check exactly what carb should be there
The FH680 had 3 fitted over its life, 2 with a square cast float bowl and one with a round pressed float bowl
The service manual lists 2 different sets of main jets for the twin barrel carb body
One has an external vent the latter has an internal vent
 

slomo

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Carb needle is obviously passing excess fuel.

I have one that pressure tests just fine. Funny but when you turn it over and install on engine, it will overfill the carb bowl and leak on the deck. Needs a new needle and seat like yours.

No other way to foul plugs in 20 minutes other than a carb needle hanging wide open. Unless you have some really weak spark??

Install an inline fuel cut off valve. Crack the valve partially open. Start and let the engine run. See if this cuts down the rich condition. Open the valve just enough to let the engine run.

Another way to test is carb right side up as installed on engine. Fill carb bowl and fuel line with fuel. Then attach your pressure tester at 7psi ONLY. See what you have.
 
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dawgslife5436

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SOLVED!!!! Put the carb back on, new plugs, new air filter. Runs perfect. Carb must of has something it it somewhere! The jets were spotless when I took it apart and cleaned it the 1st time. Very surprised it was the carb as new as it is. Thanks for all the help!
 

slomo

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SOLVED!!!! Put the carb back on, new plugs, new air filter. Runs perfect. Carb must of has something it it somewhere! The jets were spotless when I took it apart and cleaned it the 1st time. Very surprised it was the carb as new as it is. Thanks for all the help!
Guessing you might have an intermittent carb needle and seat issue. I would replace with Briggs parts and call it a day. Not much money either.

Hope she stays running good for you.
 
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