Gravely with Kawasaki & white smoke issue

jasilby

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I have a Gravely ZT HD 52 with Kawasaki FR691V. I filled tank quickly & over filled it with a bunch of spillage. The gas went down & air bubbled up as it did. I started the engine & white smoke poured out for about 6-7 seconds. I went ahead and mowed and had some sputtering or more like burps here and there at 1/4 throttle and it dies when set any lower. If throttle is all the way up it seems fine. Any ideas on what this could be? Appreciate any suggestions.
 

hlw49

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Yes it was over filled and fuel went through the roll over valve into the air filter adapter or intake pipe as they call it. Right into the engine unmetered. This could wash all the oil off the cylinder walls and cause engine damage. The roll over valve is the vent for the tank and also draws the fuel vapors into the engine to burn them. I don't know who the genius is that designed this type system and then put a notice that says do not overfill somewhere close to the fuel tank. Sure everyone is going to read the notice you have to really try to see. Disaster looking for a place to happen to happen. They need to get the roll over valve higher than the top of the filler neck of the tank. I see people fill them to the very top of the filler neck. Have seen it shoot raw gas out the exhaust pipe on the muffler. Air cooled engines are designed to run at wide open throttle to move more cooling air over the hot cylinder fins.
 

MParr

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Never put that much gas in your mower. The filler neck is anywhere from two to three inches long. Look inside your tank and you can see what I’m talking about. Only fill to the bottom off that neck. There are vent lines and fuel lines at the top of your tank. Never fill above where those likes exit the top of the tank.
 

fixit1ddh

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Yes it was over filled and fuel went through the roll over valve into the air filter adapter or intake pipe as they call it. Right into the engine unmetered. This could wash all the oil off the cylinder walls and cause engine damage. The roll over valve is the vent for the tank and also draws the fuel vapors into the engine to burn them. I don't know who the genius is that designed this type system and then put a notice that says do not overfill somewhere close to the fuel tank. Sure everyone is going to read the notice you have to really try to see. Disaster looking for a place to happen to happen. They need to get the roll over valve higher than the top of the filler neck of the tank. I see people fill them to the very top of the filler neck. Have seen it shoot raw gas out the exhaust pipe on the muffler. Air cooled engines are designed to run at wide open throttle to move more cooling air over the hot cylinder fins.
And the faster it runs the more it heats up. Use a temp Guage. We have been running our air cooled engines at 1/2 to 3/4 throttle for over 60 years with no problems. My mowers are to new. Brothers grasshopper 18hp vanguard 1999 61inch deck. He runs it at half to three quarter throttle never has had any serious engine problems. Has over 1900 hours. He has never taken blower housing off to clean cooling fins.
 

MParr

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@hlw49
The venting is due to government mandates. It’s to meet EPA standards for air pollution. There are ways around it for owners. Cap off where the vent hose enters the engine. Run the vent lines above the tank and add rollover valves there. Get a fully vented fuel cap. California standards are even worse.
 

jasilby

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Yes it was over filled and fuel went through the roll over valve into the air filter adapter or intake pipe as they call it. Right into the engine unmetered. This could wash all the oil off the cylinder walls and cause engine damage. The roll over valve is the vent for the tank and also draws the fuel vapors into the engine to burn them. I don't know who the genius is that designed this type system and then put a notice that says do not overfill somewhere close to the fuel tank. Sure everyone is going to read the notice you have to really try to see. Disaster looking for a place to happen to happen. They need to get the roll over valve higher than the top of the filler neck of the tank. I see people fill them to the very top of the filler neck. Have seen it shoot raw gas out the exhaust pipe on the muffler. Air cooled engines are designed to run at wide open throttle to move more cooling air over the hot cylinder fins.
Thank you for you’re reply & info. That for sure had to be it. Any idea why I’m having problems with low idle now? It seems to not be able to run smoothly or just dies at the lowest throttle. If I add some choke it seems to smooth out but still won’t stay running at low throttle.
 

hlw49

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Sounds like trash in the low speed circuit. I have seen welch plug come out of some of the Kawa carb. but not sure about the single bore it is mostly on the two bores on the bigger engines. Look at the top of the carb and see if any of the welch plugs are missing.
 

MParr

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Try pulling the float bowl and cleaning.
 
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