# Contemplating a Kawasaki FC420V overhaul (white smoke from muffler)



## ninensei (May 16, 2007)

*awasaki FC420V (smoking) -- What a mess I made today!*

Well, I bought a mower with a Kawasaki FC420V (actually a PB420A in a John Deere F510, but was told they are one in the same) that starts up fine. But about 20 seconds after starting, smoke starts trickling out of the muffler. 45 seconds after the engine starts, it's belching smoke like an old coal-fired locomotive! So, I am assuming that the rings are probably bad on the piston but also read somewhere that it might be the valve sleeves. Not having any prior experience, I figure the best option I have is to tear the thing open and have a look. Before I do this, does anyone have any suggestions as to things I *should* check before dismantling this thing?

The worst case scenario that I think I am willing to tackle is replacing the rings and resurfacing the cylinder. If there is more damage than that, I figure the engine is not worth saving. By the way, when I got the thing, the crank case was filled with gasoline. Unable to find a mechanical failure that would cause this to occur, I came to the conclusion that a previous owner had mistaken the oil fill tube for the gasoline tank! I don't know how long they ran the mower like this so I still don't know how much damage was actually done to the engine and transmission. I get a headache just thinking about it. The good news is that, after cleaning it all up, the engine still runs fine (with lots of smoke) and the mower moves forward and backward just fine (but it leaves a trail of black blood).

With all that said, I have been looking for overhaul parts for this engine. Can anyone suggest where to buy repair "kits" with the overhauler in mind? I'm talking about kits that would include all the common parts that would be replaced when doing certain jobs, such as a kit of gaskets when overhauling the carb, or gaskets/sleeves/rings/etc when overhauling the block. So far, I've only been able to find each piece for sale separately, and if I buy them that way, it is going to cost a fortune (might as well get a new engine).

-Steve


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## immotors (Apr 27, 2007)

Gas in the crankcase is the first thing to look at because I dought it was poored in it usually happens when the gas leaks pass the carb and into the engine this would cause all the problems your discribing. When the crankcase fills with gas it blows white smoke and due to the over fill increases crankcase pressure and the oil seals fail. Open up the carb and take a look around, smell the oil after it has set over night if it smells like gas were headed in the right direction. It will take an extended run to clear the gas from the engine once you correct the cause then you can go in and replace the seal than failed. A compression test will give you an idea of the ring condition and a good read on the plug will tell if you have a large oil burn problem.
Pat


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## ninensei (May 16, 2007)

I looked at the oil this morning. It has the smell of gasoline, but the oil is still thick (like when I put it in) so it could be just the remnant from my first gas purge.

You mentioned that gas could be getting into the crankcase from the carb. Could you be more specific? I have verified that there is no gasoline flowing through the suction tube between fuel pump and the crankcase (I installed an inline site glass). The engine runs great, so I am assuming that there is no gas flooding in from the carb. I removed the carb and cranked the engine to ensure that the fuel pump wasn't forcing gas into the engine in the absence of intake suction. I don't know how else it would get in the crankcase.

I'll try to get a leak-down tester today and test the cylinder tonight.


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## ninensei (May 16, 2007)

*Kawasaki FC420V overhaul -- What a mess I made today!*

I purchased a leak-down tester and did the test today. I'm not sure I know what I am doing because now I have a huge mess. Anyway, I screwed the gadget onto the motor, opened the oil cap and adjusted the pressure into the cylinder to 0% (supply pressure was at about 25psi) and oil just started flowing out the top of the fill tube about at the rate you pour fresh oil into the dipstick.

I then placed the oil cap back on, tightened it and tried the test again. This time, I could only hear a faint escaping of air coming somewhere below the blower/flywheel. No air coming from the carb. No air coming out of the muffler. Leakage was measuring around 20% at this time, but again, I am not sure I am setting this up correctly.

This is sounding more and more like a ring problem to me, although I am not sure why oil came out of the dipstick so furiously. Oil was between the add and full marks. Engine was cold.

Oh, also, the plug looked great. Normal wear and tear. Not fouled. No oil. No carbon buildup. Nothing. I was not expecting this considering how much smoke is billowing out of the muffler.

Any more input or suggestions?

--Steve


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