spark plug breakdown?

[cruzer]

Ahoy.. Have an 8 hp 2-stroke enduro on a dingy and after 2 years it will barely run. When new it would jump one person onto a plane and after a small struggle push two people to 15 mph. Perfect.
Last week, full throttle was hardly more than an idle. So changed plugs and it runs almost normal. Problem is: I changed plugs last month. And the month before that.
Is it possible that the coils are weak and will only fire fresh plugs? Another clue...on the struggle to plane it makes an occasional rapid fire stuttering or sputtering sound during which it does not produce full power. Coils? Engine is a month out of warranty (now theres a shocker) outboard mechanics are scarce here in Colombia (unless you want your carbs tuned with a rock) HELP Dave

[Ken]

Dave,
Sounds like you have clogged carb - I would do a shock treatment with SeaFoam or RingFree. If that does not do the trick, then do a carb teardown, cleaning, and kit install.
Used plugs are no harder to fire than fresh ones - I don't think you have "weak" coils. You are probably running a little rich due to varnish and gum buildup in the carb, and that is fouling out the plugs.
Also, check the choke on that little Yammie - it may be sticking partially closed and causing you to run rich.
Good luck [img]smile.gif[/img] ,
Ken K