Matt wrote:
I called the marina that did my drive service (they said it prob isn't
that because both would be overheating) i have never had a prob w/ them
in the past, but i expect them to say that over the phone becuase there
can be 10 other things wrong w/ it too.. There is no mussles or
anything growing (it's dry docked all year long and in fresh water)
manifolds are running about the same the one where the riser is very hot
is a little warmer but i guess that would be as a result of right?

The flaps sound fine, i hear no clacking...

I can check the cooler, but again, at the end of last season all was
fine, winterized it, then had it serviced few weeks ago, then the start
of my problems...

I pulled the hoses to the risers while the engine was on to check the
flow, the 'hot' riser had a little less flow but nothing major, this was
all while on the earmuffs...

I'm clueless... I am dreading bringing it back to the marina the
TELLING them to redo the impeller or recheck it.. I really don't want to
do it myself, it's such a pain in the ass and i need two people for it...


"jim 0010" wrote in message
...
Matt wrote:
It was stored with coolant run through (same as i do every year)
There are no metering balls in the housing, and i toolk the entire
housing apart, everything looks good. Hose's are definately not
reversed. Manifolds/Risers are only 3 years old, fresh water use
only. I inspected the riser and looks good.


"jim 0010" wrote in message
...
Matt wrote:
Hi,

I have a 94' Chaparral w/a 5.7L Mercruiser 350MAG. Looking for
some advice on pinpointing a problem. Here's the story:

Last year everything was running fine. Beginning of this season i
had the outdrive/impeller serviced. After dropping it in the water
i noticed that one Riser gets extremely hot. This is def not the
norm. The temp is constant at 160 (thermostat setting). I took off
the entire thermostat housing (everything was fine), replaced the
thermostat, took off the Riser (everything fine), checked the
exhaust flaps (everything fine), and all hoses looked good. I
can't figure out what could be the problem. My two thoughts,
either something happened over the course of the winter, but what?
or when the marina serviced the outdrive something got screwed
up. but if it was an water intake problem wouldn't both risers
get really hot?

Any help troubleshooting is greatly appreciated.

Thanks!!



The first thing to be suspicious of is the work that was just done.
Did you store the engine wet or dry? Dry storage can cause excessive
internal rusting. Rust particles could be clogging a riser or the
riser itself has rusted out and clogged. If your engine has metering
balls in the thermostat housing, they could be worn or where they
seat on the housing could be eroded. Is it possible that you have 2
hoses reversed.

I would go to the water pump and check it carefully, including the
part the copper tube sticks out, of in the upper unit. It might have
melted during an overheat episode. Also make sure the guy used the
right rebuild kit. Make sure the 3/4 diam water hose in the bell
housing isn't kinked or cracked. Make sure you don't have mussels or
vegatation clogging the water pickup vents. Is one manifold much
hotter than the other? Make sure your timing is set correctly. Make
sure some broken impeller pieces aren't blocking the power steering
cooler. Are your exast shutters clacking noticeably?

As long as you have sufficient water pressure to the muffs and you arent
running the engine more than a fast idle, there's nothing more to check
without pulling the drive off. Check the oil cooler to be sure there are
no blockages. you don't want them sandbagging you when you bring it in
for service. If they come back and say the problem is something you
already checked then you have a problem with your assessment or the
dealership's honesty.
Good luck.