On Mon, 14 Jun 2004 22:58:16 GMT, "JamesgangNC"
wrote:

I've never heard of the engine speed having anything to do with the silent
choice exhaust. They are just Y connectors with flaps in them. Most are
big electric solenoids but there are also hydralic ones. The corsa ones are
solenoids, I believe the merc silent choice are also solenoids. I flip my
corsa ones on at WOT all the time. Sounds like an bad connection or relay.
They often have one or more relays because the electrical load is too big
for a dash switch.

Thru-hull exhaust is *required* for the Mercruiser 454 and 502 Mag
motors. Under 2000 rpm, you're fine thru the prop, but above you have
to switch to thru hull. You could probably get away with higher rpms
thru prop, but definitelly not WOT. If you do, you lose not only
performance, but risk engine damage.

I hope you've got something less than a 454 Mag?

That said, i don't think flipping the exhaust at higher rpms should
cause damage to diverters themselves. Check the relays like the above
poster said.