On Sat, 02 Oct 2004 20:49:58 -0400, JohnH
wrote:

On Sun, 03 Oct 2004 00:19:13 GMT, Short Wave Sportfishing
wrote:

On Sat, 02 Oct 2004 20:05:32 -0400, JohnH
wrote:

~~ snippage ~~

Tom, do you have any idea what the temperature of a riser should be on a warm
5.7L Mercruiser? Should there be a difference in the temperatures of the two?
The mechanic at my marina told me the starboard riser will run hotter than the
port. Any knowledge of this?

No, although the engines I've seen serviced by shop technicians
usually run between 90/110º - anything above 130º is considered
suspect but that's not an official temperature - it's just an
observation on my part.

As to differences between risers, I'm not sure why that would happen
and would love to hear if there is a difference and why. I've never
heard anything about a difference being normal.

The mechanic said something to the effect that the water from the circulating
pump gets to the port manifold first. (?) I didn't go look at the cooling system
to see if that made sense, and I can't find enough detail on the web to verify
or disprove it. The thermostat is 160 degrees. That would seem to imply that the
surface temp of the riser, which is cooled with that water and heated with
exhaust gases, would be somewhere in that ballpark. But there is a noticeable
(to the touch) difference between the temps of the two risers. I'd guess 15
degrees or so. (My temp sensors in fingers have not been calibrated, however.)

Well, I can't say myself - just don't have the experience with
inboards that I would have liked to have. Almost all the engines on
boats I've owned have been outboards - I've only owned one inboard and
the only thing I did to that boat was rebuild the engine. I sold the
boat three months after I bought it.

However, I did know a guy who had a very accurate torgue arm. He
could nail torgue values up to about 40 lbs. I don't know if he can
still do it or not.

Later,

Tom