BoatBanter.com - View Single Post - merc 302 v8 i/o shake,rattle, but no go.. need help!

(tj) wrote in message m...
symptoms: when starting out from idle upon opening throttle, boat
vibrates and rattles but fails to produce adequate thrust. Prop turns
but only generates minimal movement through the water. Engine revs at
high rpms but fails to accelerate through the water.

Attempted Fixes: rebuilt carberator, flushed the fuel, replaced fuel
filter, replaced the batteries, replaced the starter, replaced 12v
coil, replaced the ring gear on fly wheel, replaced the coupler, even
replaced the spark plugs.
Note: when replacing the gear on the fly wheel, engine was pulled and
replaced, without removing the stern drive

Note: Boat was purchased roughly 1 month ago with rebuilt engine and
currently has 62 hours on it.

Possible Diagnosis:
could be ignition
could be drive unit slippage
prop cavitation / ventilation

Still searching for an answer. Any help that could be provided would
be greately appreciated.

You need to tell whoever is helping you to go home, and take the boat
to a qualified mechanic. If you would like me to go into why, I will,
but you won't like my reasons. For now suffice it to say that you have
spent more on "repairs" than having it done professionally would have
cost. Sorry to seem harsh, but you need to stop wasting lots of money
on expensive parts and start enjoying the boat.