big problem

[alexfisk19]

i got a 1998 four winns with a small block motor and the volvo penta inboard outboard drive.
thats all fine its just after driving for about 15 mins full speed it over heats. whats the deal??

 

[Docksidemarineservices]

When was the last time the water pump was changed?

 

[alexfisk19]

well its a brand new motor. we bought the boat with out a motor and put in the small block. but cannot seem to keep it running cool. but as soon as you let off in about two mins it drops right back down and is cool again.

 

[Docksidemarineservices]

Did you purchase a complete drop in Marine engine or did you purchase a long block?

 

[alexfisk19]

noo it is not a marine motor it is a normal street long block that has been converted

 

[Docksidemarineservices]

Converted in what way? Does it have a marine camshaft? It's not just core plugs and head gaskets that make it a marine engine. It's also the cam shaft, Compression ratio and the SS valves. Did you replace the impeller in the raw water pump?

 

[alexfisk19]

Would any of that also nake it sound like its out of timing??

 

[Docksidemarineservices]

What kind of sounds are you hearing?

 

[alexfisk19]

When you floor it quick it pops and sputters and doesn't go. That's another problem out side of the overheating. Its a brand new impller and everything so I'm stuck

 

[Docksidemarineservices]

The abrupt full throttle poping and sputtering could be an accelerator pump issue. What is your total timing? I would not recommend giving abrupt full throttle on any boat. As for the over heat, The water that comes in has to leave the boat. I would look for an obstruction. Also what condition was the water pump housing in? Was it smooth inside or showing signs of wear?