Kawasaki FH721V blowing smoke

[floyd r turbo]

That's a great explanation for all that smoke, thanks for the input.

 

[smallenginerepairs]

I bought the mower last year used from a reputable Hustler dealer who said it was owner's personal mower traded in on a larger model and he was a service manager who used dealer shop for maintenance. Oil was super clean as well as the mower. I used it end of last season. Just drained oil tonight and smelled like gas and its very thin, like oil has been diluted. I tried to find and initial response on internet that carb could have flooded and diluted oil in crankcase but haven't been able to find that article again. Before changing oil I've run the motor for under a minute a few times - initially I was having the heavy smoke and now that's gone away it was starting better but was concerned about damaging motor until I find problem. So maybe the float was stuck causing that white smoke? then straightened out but diluted crankcase oil. So putting in fresh oil/filter. and will start over in AM to run it and see if its still smoking with the fresh oil. Hope cylinder walls haven't been scored or worse, bearings scored. I thought if carb was flooding, motor would run rich or not at all. Still baffled. By the way, fins are clean, I blow mower off after mowing and when cool, I'll sometimes hose it down. I'm cognizant of motor and trans cooler must be kept clean and in top shape for longevity. Appreciate all comments and always learning so don't hesitate to hit me with you thoughts. I'll continue to update this thread for the record.

The float in the carb will overflow the carb, will enter the cylinder and end up in the oil. I put a gas shut-off valve on all my riders and never have to worry about that issue. It also helps when putting it away for the season. I leave the fuel shut off and run the engine until it dies. I then empty the fuel tank and I don't have to clean my carb each new season. Unleaded fuel begins to breakdown after 3 months. If you leave fuel in your mower at the end of the summer cutting season, your carb will need cleaning in the spring. On all my equipment:rider mowers, push mowers, chainsaws, weed whips etc., i always drain the fuel tanks and run the engines till they die, to drain the carbs, and when I put new fuel in them in the spring, I never have a carb problem with them !!

 

[Cajun power]

334 hrs

past time to do the valve clearance maintenance. get the kawasaki service manual. And be aware there is a KNOWN error in the service manual with respect to valve clearance gap! If you have questions about this, you will not be the first person to notice there is an error in the kawasaki manuals and even the service manual. So get good advice from people who know what the valve clearance should be and some tips and tricks on how to find proper Top Dead Center. on my FR691V's (I have 3 mowers with that engine, the gap is .004 inches..both exhaust and intake. and top dead center is located PER THE SERVICE MANUAL by rotating the flywheel CLOCKWISE (as you are looking at it from above the flywheel standing over it). In the service manual, there is a diagram showing where top dead center is in relation to the flywheel magnet and the coils assembly. Follow that. Some will advise a gap slightly larger for the intake at .005 inches. You mileage on that advise will vary. I use .004 inches for both and it passes leak down every time, so that is good enough for me.

according to the service manual and also my experience, it is a good idea to remove the cylinder heads and clean all the soot and relap the valve and inspect them to make sure the valve seats are not damaged or valve stuck open and REPLACE the cylinder head gaskets. I use ONLY copper gaskets...it's better heat transfer, a better fit, and better squish and cheaper than the junk kawasaki OEM head gaskets...even over the so called "improved" kawasaki composite head gaskets (simple stamped aluminum with the fiber embed). Use a torque wrench and sequence to tighten the head cylinder. Don't guess. (you may also want to cheap for head cylinder warp on mating surfaces per the manual too. A simple metal straight ruler in the dark with a flashlight is all you need to find out of plane mating surfaces. If you see light, you have a problem. Do this across several angles over each mating surface. While rare, cylinder heads can warp...especially when they run really really hot and you get stuck in a unexpected cold rain down pour..or your idiot cousin insists on washing down a very hot engine with the hose every time he mows (don't ask!)

For my kawasaki engines I use 10w-40...for the high hour machines, it's 10W-50. Synthetic. If you run them hard, and often, do frequent oil and filter changes...I do it every 50 hours of operation. Oil and filters are cheap. These are air cooled engines. clean oil helps the life of these engines more than just about anything else.

I always shut the engine off using a fuel cutoff valve. I do this because fuel in the carb during storage causes problems with gumming. Installing a fuel shutoff valve is easy. I put it right before the fuel pump.