I have a Honda BF15A I use for trolling. It worked great for several years but recently it will not idle. It happene once before and I adjusted the mixture screw on the carberator which fixed it at that time but now I cannot get it to idle at all. It will run at high speed but as soon as I try to slow it down, it stops comlpletely. I replaced the fuel filter and the spark plugs. Any other suggestions before I take it to a mechanic?

