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View Full Version : Kaw FB460 wierd starting


B&A lawn care
08-01-2008, 09:57 AM
I resurrected a VERY neglected Exmark with a FB460 and it has a starting problem that mystifies me. When I bought it it would not start and found several things causing it including the exhaust valve clearance which had closed up to the point of holding the valve open all the time. I corrected the clearance and reconditioned the valve and seat and it will 90% of the time start on the first pull. If it does not start on the first pull you are in for some excersize for your arm and a test of holding your tongue. In every case starting or not, that first hit sounds like it is about half firing right straight out the exhaust with a popping noise but most of the time it will kick the motor over and it will then run (engine runs like a top) If it does not kick it over and run on that first try it will pop out the exhaust on most pulls but wont kick over and run. If you leave it sit about 5 minutes it wil start (most of the time) Coil and ignitor are both new, plug has been changed twice. Magnets seem to be OK, dont know how to check them. Checked the valves again, both seated. Anyone want to throw some ideas at me? The darned thing runs too good once it iis going to pitch it but I am about at that point. (I have found few people that are willing to pay me while trying to start the dang mowers)

Phil G
08-01-2008, 05:35 PM
If it's popping out the exhaust then the valve may not be closing fully. Either the valve gap is too small or more than likely the valve stem is sticking, holding it back from closing. The valve stem should be nice and clean and bright. Assuming the ignition is 100&% as that can cause popping under some circumstances.
Good luck Phil
What engine is this?

Two Seasons
08-01-2008, 10:22 PM
If you can get it going again, you could put some seafoam in the gas and run it that way for the rest of the week.

Seafoam says that it removes carbon from the combustion chambers.

Phil G
08-02-2008, 01:26 AM
If you can get it going again, you could put some seafoam in the gas and run it that way for the rest of the week.

Seafoam says that it removes carbon from the combustion chambers.

Smart idea :)
Just a thought, if you do get it running in your normal way, when you shut the engine down, pull it over to compression stroke. This way both valves will be closed and if the stem was sticking this should avoid it the next start-up
Good luck Phil:usflag: