kawasaki fc420v fuel delivery problem

Discussion in 'Mechanic and Repair' started by nematoad, Jun 7, 2007.

  1. nematoad

    nematoad LawnSite Member
    Posts: 21

    Well, I finally got my John deere running (see "weak spark" thread), it ran for about an hour and then backfired twice made a funny scraping sound and quit. Now it won't start again, but after replacing the spark plug (mmm hmm) and checking for spark (that was ok) I find that the plug is not getting the least bit wet, even when choking. The fuel pump is fine the fuel filter is fine and there is gas in the float bowl. Apparently it isn't getting gas, but I don't know if it is a carb problem or something more sinister like valves or even worse cylinder / piston. Before I have the carb rebuilt is there anything I can do to check on other possibilities? Any help is appreciated.
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    It most likely sucked a piece of trash into the main jet. Drop the bowl and spray carb choke cleaner with the straw up into the center where the bowl nut screws in and any other ports/passages you see. If you have a compressor blow it out, Re-assemble and try again. Check your tank for trash also.
     
  3. nematoad

    nematoad LawnSite Member
    Posts: 21

    Will do restrorob. I'll let ya know if it works. Thanks again.
     
  4. nematoad

    nematoad LawnSite Member
    Posts: 21

    No joy on the main jet cleaning, restrorob. I took off the float bowl, squirted carb cleaner up in the direction of the main jet and at different angles, then blew compressed air up there. Put it back together, but it still won't start. The plug is still dry. If I squirt starter fluid into the carb throat it will backfire loudly one time. The backfire seems to be coming out of the carb and the muffler. Any other suggestions?
     
  5. nematoad

    nematoad LawnSite Member
    Posts: 21

    Bad news. I decided to take the head cover off and have a look and I found a broken part in there. It is a thin ring shaped piece (only found half of it), to me it looks like maybe a retainer. Could be the spring retainer. I know this is bad. Is there any use pursuing this any further or should I lay the old girl to rest? It is 20 years old. I suppose I could tear it down and rebuild it but it would require a lot of time and tools I don't have access to. In the meantime the grass is getting taller. What is the general consensus out there?
     
  6. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    If it was running OK before the retainer broke I would replace it and run it some more.

    You can do this without removing the head. Rotate the engine by hand to top dead center compression stroke. Remove the spark plug and stick a small screw driver in the hole touching the top of the piston for a gage, Rotate the piston BACK down the cylinder about two inches. Insert 5 to 6 inches of #5 recoil rope (only use recoil rope) into the plug hole on top of the piston making sure to have enough hanging out for removal, Then rotate the piston back up till it hits the rope. This will hold the valves in place providing the piston doesn't move.

    Loosen the rocker arm adjuster and move the push-rod to the side and flip the rocker up out of the way of the spring. Install the new retainer on the spring and with a thumb on each side push the spring/retainer down onto the valve stem and have a buddy install the keeper. Put the rocker back in place then the push-rod and just snug the adjuster for now. Move the piston back down the cylinder and pull the rope out. Rotate the piston back to TDC compression stroke then adjust both valves to spec. and off you go to mow.

    Here is the adjustment procedure;

    [​IMG]
     
  7. nematoad

    nematoad LawnSite Member
    Posts: 21

    Well restrorob, I appreciate your info on replacing the spring retainers, however I think I may be headed for a rebuild or the junk yard. I've attached some digital photos of what I found behind the valve cover. The first picture shows damage to the head where the spring is seated. The second pic shows the area "I" where the retainer seems to be missing and "II" the retainer on the good valve. The x marks the area where the damage to the head has occured on the exhaust valve assembly. Finally, the third pic shows the remainders of the broken pieces I found behind the cover. (except for the penny, :laugh: ) I fear some of the metal may have ended up behind the push rods in the crankcase! I guess a rebuild is my only option now. What do you think? Thanks again for your patience.

    scored area.jpg

    Compare valves.jpg

    Broken parts.jpg
     
  8. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Well, There's still hope for this engine !

    The so called damage to the head is nothing more than the "Spring Seat", The pieces you found is part of this "Spring Seat" and if you do as I out-lined above with the rope and remove the keepers, "Retainer" and spring you will most likely find the rest of the "Spring Seat" still under the valve spring.

    There is nothing wrong between the looks of the "Retainers", They are designed differently between the intake and exhaust valves.

    You could just replace both intake and exhaust "Spring Seats" part# 16007-2073 and both valve stem seals part# 92049-2223 (while your there) and slap it back together then set the valve clearance and go mow.


    [​IMG]
     
  9. nematoad

    nematoad LawnSite Member
    Posts: 21

    Sounds like a good plan. Thanks for the important info and the encouragement. I would have never known how to, or attempted to fix it otherwise. I will give it my best shot. One last thing, though: if some of those metal fragments got in behind the push rods would they end up in the crankcase and possibly wreak havoc in there? I am going to try to fix it regardless, but wondered what you thought about that.
     
  10. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Well, It depends on how much/big the pieces are. Get the rest of it from under the spring and make believe it's a puzzle and see how much is really missing. Looking at the last pic it appears that half is intact, This seat is made from stamped steel so I wouldn't think it would break into small pieces.

    Post a pic with it along side of the one from the intake then take it from there.
     

Share This Page