My 1981 (I think) 40 HP Mariner (Japanese-made) has started bogging down badly under a load. Like getting no gas. I've done the standard change plugs and replace gas line/bulb, check filter, etc. Two people have told me the fuel injection ports are probably clogged. Is there a way to effectively check that and clean them WITHOUT tearing into engine? I am no mechanic, I barely know a flathead from a Philips head. I've read some other posts about how to clean carbon buildup using Seafoam, but those seem directed toward cleaning chambers. Can the same process, or another, be used to clean injection ports. Or should I bite the bullet and pay someone who knows what they're doing?