Suspect broken intake valve spring

[Scott Lynds]

Hi, Our engine fires up and idles well, but when we try to accelerate, the engine won't "take the gas", and spits and sputters and dies. When we pull the plugs and look at them, the plugs from the 3 and 4 cylinders are wet, while the ones from 1 and 2 are sooty. We have confirmed we have spark at all cylinders, and the compresseion is good in all cylinders. We are wondering if perhaps we have broken intake valve springs on 3 and 4? If so, does the engine have to come out of the boat to chage them (Ericson 29), and does the head have to come off to get at them? Also, what side of the engine are the intake valves on?
Thanks, Scott

[rgoff]

Those are the same symptoms I had when my exhaust system was clogged. Loosen the exhaust pipe from the engine and see if that cures the problem. Don't run it for long, however, as it will be loud and smelly.

Good luck,