jsoderbe

Hi, just bought a Wellcraft with a 375 hp 496 MPI engine in it. It runs great, looks great, anf the temp needle is rock solid in the middle of the gauge. While sea trialing it I noticed some steam from the left exhaust when I floored it. I could easily hold my hands on the risers after a 55 mph run, but cant help to feel that they are a bit hotter than they should be. My other boat has very cool risers.

The 496 has the closed cooling system, so the risers looks different. Since this is my first engine with fresh water cooling I am not sure what is normal or not. Do the risers wear out the same as in sea water system?
The PO lived in a brackish river, and dit not flush the system.

Any thoughts?

Regards,

Johan

Randy Nielsen

iTrader: (4)

The only problem I ever had with running hot or overheating on my 496s was when the oil cooler got partially plugged on one engine. I pulled the hose from the heat exchanger & backflushed it out and that took care of it. I did notice that one manifold would run about 20* hotter than the other on both engines but it never caused a problem. I believe the manifolds are aluminum & the risers are painted stainless on the 496s. Hope that helps . Randy

SDFever

The risers have always been painted stainless steel. They will last many years. The manifolds can either be aluminum (earlier models) or cast iron. Yes, the system will feel slightly hotter to the hand then a standard open cooled system. Also possible there is some sand or build-up in the "left" exhaust that might be restricting flow. If it's in cool water it's normal to see a little steam. The port side always runs hotter by way of design flow from the heat exchanger.

Hard to tell from your info which side you are calling "left".

jsoderbe

Hi guys,

thanks, then everything seems ok. I watched it at startup today, and the water first exited the starboard side exhaust, then a few seconds later the port side. It is correct that the port side is warmer, but still not hot. Thanks for your help!

I have another issue, a high-pitch squeal, but I will start a separate thread about that.


Regards,

Johan