[rsimms]

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?

[mellowyellow]

sounds like a carb rebuild is in order. if u rnot comfortable, take it in and have it serviced.specifically ask for carb rebuild...good luck,M.Y.

[COLDWATER]

no#1 compressoin check if ok go for the carbs

[rodbolt]

hello if your not real comfortable doing the carbs yourself and the jap motor was a bit difficult, then take it to a pro. not joe schmucatelly on the corner either. be sure to explain when it ran ok last when it started running poorly did it ever overheat,did it ever sink, remember you can lie to your wife,yourlawyer and your minister but a competent tech will eventually figgue it out. I have them all the time. good luck and keep posting but trust me the more information you give the faster and better the tech can pinpoint the problem.

[rsimms]

Thanks for advice... I'm more baffled now. I took it out last night and it ran great. But it's 22 years old so I suppose a carb rebuild is probably in order regardless. But I typically subscribe to theory, "if it ain't broke, don't fix it." I'll rethink that someday when I'm broke down 5 miles from the launching ramp. <grin>