alarm (continuous)at high rpm 92 40 hp mercury

[hydrick]

i bought a 92 40 hp saturday.the owner assured that a year ago a new impellar was installed, and boat checked good.
my problem is at full throtttle after about 3 minutes a constant audible alarm will sound.
if i come back to idle it alarm stops.
take off again same thing.
at idle no alarm.1/2 throttle doesn't seem to trigger it as quick,if at all.
for the record when first cranked 10-20 seconds pass before water starts at pee hole.good strong stream.
the faster i go the stronger the stream gets.
i'm at a loss for what's going on.

 

[joed]

Re: alarm (continuous)at high rpm 92 40 hp mercury

Continuous alarm is the overheat. Perhaps the water jacket is partially clogged with old impellar or dirt. Perhaps the water exit passages are partially clogged.

 

[hydrick]

Re: alarm (continuous)at high rpm 92 40 hp mercury

the first day i had the depth finder on too,i thought the alarm was the depth warning so i'd cut it off and the alarm would stop(irony)who knows,lol
day two the only way to stop it is come off wide open throttle.
i left it idling for 30 minutes with no alarm.

 

[hydrick]

Re: alarm (continuous)at high rpm 92 40 hp mercury

i'm curious.....would a hydro foil cause problem at high speed with water intake?

 

[hydrick]

Re: alarm (continuous)at high rpm 92 40 hp mercury

it's official.
i talked to a boat mechanic that knows for fact this boat was cranked while out of water.the owner left keys in switch with a strong battery.
i'm replacing impellar tomorrow.