ST31

Went to start up the boat Sunday and noticed gray smoke and what smelt like fuel coming from the right side exhaust. I checked the oil, temp, and drive fluids, but all appear to be normal. There also seemed to be maybe a chalk type residue as well? How bad is it?

ST31

tt

JaayTeee

Is it a VST setup?
if so, the VST vents right into
the #8 intake runner, if its
leaking, it will dump fuel right
into that runner.

jt

Cord

iTrader: (2)

I saw a 575efi this past weekend that was running incredibly rich. So rich, that it was smoking like a diesel. The owner took it to the Mercury trailer where they found the map sensor had come unplugged. Don't know if it's your problem, but it would be something to look into.

ST31

It is a VST setup. That was my first thought. Is there an easy way for me to check it?

JaayTeee

Put a clear piece of tubing
in place of the hose, you
should be able to see fuel
travelling through the tube
if it's leaking.

jt

ST31

If it is the problem, how hard is it to replace?

JaayTeee

I wouldn't replace it, kinda pricey,
I would install the necessary repair
kits needed.
The VST removes fairly easy,
lines, and electrical plugs.

BAM marines website shows the
items you may need.

A freind had to install a
diaphram kit in his VST, for a "similar"
condition.

jt

RonS

diapragm kit is about 50.00, You will also need the o-ring kit, 70.00 from merc, the only one you need is the one for the top cover, sometimes you can reuse it, but depending on how old it is, it may be stretched out and not stay in the groove.

All in all its pretty simple to do.

ST31

Thanks for the help. Does anyone know of any diagrams that I can use for reference before starting the job.