I am a new owner of a used 2005...

[Markastone]

I am a new owner of a used 2005 200 Sport with a carberated 5 liter.  What temperature should I be running?  For my first trip today in a fresh water lake it ran about 200...is that expected?  It has 175 hours if that’s important.

Thanks in advance.

[wingless]

Welcome to the forum.

Good luck w/ your new boat.

That temperature is higher than expected.

There are many systems to remove heat from the running engine that must operate properly.

The assuming a fresh water cooled engine (antifreeze), then raw water is drawn in to cool the fuel, antifreeze and exhaust, plus other systems.

Is there good raw water flow? Has the exhaust been disassembled to inspect for internal corrosion? Can the exhaust be continuously hand held while the engine is running, not too hot?

[t-bone]

In addition to the items wingless suggests, which are spot-on, one of the cheapest and easiest thing to check first is the thermostat. I had a similar issue, after after trying everything to no avail, it finally dawned on me to replace it. Still feel dumb about it to this day, but happy to find the cause.

[Trev]

I have a 2008 205 sport 5.0 and it runs around temp 175. Good feedback from t-bone/winglesss.

[Rafy]

Hello, a SD 200 4.3 mpi, was running @190-200, replaced 1 rusty riser, it runs all day 150-175 degrees, hope it helps!

[Scott3262]

Also in addition to the above, when was the impeller changed last?

[RonB001]

I have a 99 210 Sundeck with the same engine (5.0, 2bbl, 220 hp), and it normally runs 170. It might go up to 175 during a hard run.

Comment on wingless: The fuel cooling is only there on the fuel injected engines.

[Rafy]

..Good point Scott3262, my impeller was the first and easiest part to check, it was in good shape, I never checked the thermostat because the cooling system was working fine when water tested after replacing 1 riser...

[Rafy]

Also, years ago after replacing an impeller on a 5.0 Mercruiser and still overheating, I found pieces of rubber from the impeller clogging the cooling lines...

[Markastone]

Thanks everyone for the advice! I’ll start with the thermostat...