Ya... sounds like a fuel flow issue somewhere. Make sure the gast tank vent
is open... and then work your way clean - all the way to the intake
manifold. You're bound to catch it.

-W

"basskisser" wrote in message
ups.com...
On Apr 5, 11:49 am, wrote:
I have a 1994 Proline WA with a Mercury Outboard 225 hp....I have
changed all spark plugs, gas filter, and throttle cables. My boat
starts up perfect and purrs like a kitten, but as soon as i begin to
open her up and she reaches 4500 or a little more she begins to go
crazy...the RPMS begin to rapidily decrease and re-increase...and this
wont stop....it is so upsetting..i have to place her back in idle and
then slowly get her back up to 4000 rpms and cruise with her
there...at 4000 rpms im cruising at about 27 mph but i should be
cruising at 32-35 mph's... someone please help

I'd put my money on a carb rebuild.