audible alarm at no wake speed

[abaker]

I have a 2001 four winns 254 funship with a 5.7 Volvo Penta. After spending several hours on the lake i began experiencing an audible alarm when i throttle down to no wake speed. Gauges did not indicate any problem with oil pressure or overheating and engine oil was good. Alarm stopped when I shut down engine and restarted but came back on after running at speed then coming back down to no wake speed again. Please help.

 

[Don S]

Re: audible alarm at no wake speed

When was the last time the impeller in the raw water pump were replaced?
The engine mat be getting just enough water to stay cool, but one of the temp overheat switches in the risers is telling you there isn't enough water in that riser.
They do act as an early warning for worn imprellers and clogged exhaust.

 

[abaker]

Re: audible alarm at no wake speed

I'm not sure, I just bought this boat and this was my first outing on it. It performed flawlessly for about 41/2 hours prior to getting the alarm.

 

[Don S]

Re: audible alarm at no wake speed

If you don't know the history, replace the impeller.

 

[abaker]

Re: audible alarm at no wake speed

Ok, thank you

 

[abaker]

Re: audible alarm at no wake speed

I pulled the pump but the only part number I can find is on the impellar itself, nothing on the housing. The impellar part number is Volvo penta 3862465. I can't find that part number anywhere, can you help? Is there a replacement number? And the impellar was missing 1 1/2 fins and i can't find them, do you know where to look for them.

 

[Vinnys]

Re: audible alarm at no wake speed

Bring the damaged impeller to the local Penta dealer along with the engine information. Model and serial numbers usually help a lot.
As for parts of impeller it might be a good time, since you probably haven't yet, is to flush the engine and any related cooling system parts. That should remove any small bits of rubber if they did not exit on their own.
Don't be lax with impellers. I have seen bad impellers be the root to engines filling with water due to syphon effect.

The more info you give about engine make models drive etc. on the first post will get you more thorough help too.

Good luck

Vinny