I just bought a like brand new Johnson 4 HP. I knew the fuel line and carb. would be plugged up with old fuel when I got it. My problem is I can't get the front lower shroud off the choke and fuel tank switch so I can get to the carb. I have taken everything loose but the shroud will not fit over the choke knob. The little motor runs perfectly when I squirt premix into the air cleaner but it won't continue to run on its own on either the internal tank or the remote tank so I'm pretty sure the float valve it stuck with old fuel. I just can't get to it. Is there a trick to getting the shroud off? Any help would be greatly appreciated. Thanks, Cushman45