Larry wrote:
"Scott" wrote in news:1151259695.135952.325400
@p79g2000cwp.googlegroups.com:

Have a 14' fiberglass boat with a Suzuki DT40. The hull is very old,
it's a 57. The motor is a late 80's. Motor runs great but when I get
over about 60% power the bow of the boat intermittently "dives" left
and downward abruptly. Very scarey. The prop is in bad shape. Would
this be the source?



Lay the hull on its side and look all along the bottom to see what's
"loose". It sounds like something on the port side of the keel, probably
towards the stern of the boat, is coming loose and causing a drag on the
port side, which will cause the stern to rise, the bow to dive and the boat
to swing uncontrollably to port.....

Are there trim tabs in back? Are they loose? HOw about an external sonar
transducer or even a speedometer tube mount? Something's dragging down the
port stern like a spoiler opening to slow an airplane abruptly.

The prop is just wasting power at any speed. Gas is $4/gallon at marinas,
now. It's an economic decision to change to a nice prop, eh?

Larry,

Looks like you nailed it. I had an old Hummingbird transducer on the
port side. It was 2.5" x 3" which apparently caused the strange
handling. Nice call!

Scott