Thanks for the feedback. It does have a mechanical fuel pump, though I don't
know if it is high or low pressure, and I'm sure I could plug this line with
a fitting, but I wantr to make sure it is fixed right. I have been told this
line is a vent for in case the diaphragm ruptures. Fuel would vent into the
carbeurator instead of spilling into the bilge. This make perfect sense to
me except I have never seen a fuel pump with a ruptured diaphragm that
supplied fuel. I thought a rupture would prevent any pumping action at all,
but it has been suggested to me that they can continue to pump fuel through
the "vent" which is exactly what this one seems to be doing. In any case,
I'm going to try replacing the pump and see what happens. Thanks again for
taking the time to respond to my problem.

"Brian Whatcott" wrote in message
...
On Sun, 10 Jul 2005 06:21:02 GMT, "Kevin Jed"
wrote:

I have a Mercruiser 120 fuel problem. There is a small tube going from the
fuel pump to the throat of the carburetor (like a vacuum tube) and it is
injecting a large volume of fuel into the carburetor throat, bypassing the
float assembly altogether and flooding the engine. When I remove this tube
and attempt to plug it, the engine runs properly but there is so much
pressure on this little tube it blows the plug out and starts pouring raw
fuel into the boat! Automotive engines don't have this tube, and I don't
know what it's purpose is. Can anyone offer any help? Thanks!



I think that older Mercruiser 120s had a low pressure mechanical pump.
Is this true of yours?
If so, a small length of fuel pipe, with a blanking plug at one end
(even a wood screw would serve to test) and secured with pipe clamps
should serve the purpose.

Brian Whatcott Altus OK