Kawasaki FB460V hunts/misses/backfires.
Hey guys, got a real tough one here. I got a free John Deere SX95 riding mower a few years ago. It was non running and needed a lot of work. Well, long story short both the ignition coil and igniter were bad and needed replacing. I priced the parts out from both John Deere and Kawasaki and the prices were absurd for both parts(like $60 for the igniter and $80 for the coil). I ended up going with aftermarket units for less than half the price which seem to work fine. When I first got it running, it ran nice and smoooth. Idled perfect too.
All of a sudden, it started to rev up and down, backfire, and misfire no matter where you put the throttle. It will not idle for anything. The only thing that made it better was if you choke it slightly and it would smooth right out.
Cleaned the carb(several times), changed the plug(gapped it), decarboned the head, tried fresh gas, bypassed the fuel tank, checked the fuel pump,and replaced the air filter with no luck.
BUT when I engage the mower deck, the engine smooths right out. It runs fine under load, but when its not under load, it runs like crap. The worst part is now it is drinking gas at an alarming rate. I only have around 2 acres to cut and by the time I am done, the tank is almost dry. I would guess the tank is a good 1.5 gallons or so. That is a heck of a lot of gas to cut my grass. At 4.XX a gallon, it gets expensive quick if you are cutting your grass 1-2 times a week.
I am pretty much at loss what the problem could be. I love this machine but it is just driving me crazy. I know its not supposed to run like that.
Thanks in advance for any advice.