Kawasaki FB460 hard to start, rough running long post.

Discussion in 'Mechanic and Repair' started by B&A lawn care, May 27, 2008.

  1. B&A lawn care

    B&A lawn care LawnSite Member
    Messages: 70

    Well I have been searching your forum but cant figure out this 12.5 HP Kawasaki so I joined up this evening. I will try to give enough info here for the experts to figure the dang thing out. I recently bought an Exmark walk behind used, know nothing about it other than it appears to have little use but has never seen the inside of a shed. When I bought it the guy pulled the rope once and it ran like new. Get it home and it wont start. Once in a while it would pop out the exhaust but only when choked. Plug is wet with fuel after attempting to start with choke on. Bought a new plug and checked spark, kinda weak looking but there. Engine started after removed the recoil and spun with my big drill. After it started it ran like the choke was 2/3 closed. Shut off and took the bowl off the carb and checked the float, needleand seat. Everything was clean. Started again (with drill) This time I had the air cleaner off and there is a tremendous back flow (for lack of better description) down in the carb, like its trying to blow fuel backwards out the carb. The engine ran rough like that for a minute and then suddenly started to run correctly with just a little blow back into the carb. Mowed a half acre with it and ran fine. Shut it off and no start again. Checked plug and no spark. I then unhooked the safety shut off system to check it and still no spark. From this forum I leaned about the Kawasaki "ignitor" and the woes it causes. I bought one and still no spark. My dealer said they always replace ignitor and coil together. Bought a coil and had spark, still kind of weak like it was at first, but there. Tried to start it with the rope and would spit out the exhaust now and then and thats it. Changed plug again and same. Hooked up the drill again and spun it. would not fire at all unless choked and then spits and sputters like flooded and spitting fuel back out the carb. I shut the fuel valve off while running and it ran the same until it died from lack of fuel. If I let it run a minute or two it will clear up and run decently. Will not start with the rope period. The engine pulls over easy like no compression, can hardly tell any difference with plug in or out. Has good power when runnning right and no smoke. Will not start with pull rope. Coil and ignitor was $100 and made no difference. Was has me baffled is the thing absolutely will not even pop unless choked and then once it fires, (with drill starter) it acts like it is flooded bad. If you dont choke it it will never fire and plug will be dry. Acts likes something is out of whack with the timing? Crank case shows no sign of being apart since new. About all I can think of, thanks for reading.
  2. White Gardens

    White Gardens LawnSite Fanatic
    Messages: 6,776

    You might possibly have an intake valve sticking open.
  3. B&A lawn care

    B&A lawn care LawnSite Member
    Messages: 70

    I pulled the carb after reading your suggestion and found it was blowing back past the intake valve. Problem was it had zero lash. Ground the stem for lash and lapped both valves while the head was off. Why it would run OK after warming up a bit before the repair still baffles me but it now starts on pull one every time and runs as new, thanks a million:drinkup:

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