fuel problem with straight 4 Mercruiser I/O
 

Hi,

I've got a straight four cylinder Mercruiser some info led me to believe is a
470 2bbl. 1976-1979, though other info told me it's a 140 hp 1973 Vega. I don't
know what to think about all that, and I'm sure no mechanic. Anyway, since the
weather has gotten cooler it no longer will idle, though the temperature may
have nothing to do with it. I'm in GA around Atlanta so it's not very cold. It
has a clear inline fuel filter that got real dirty so I changed it, but it still
won't idle. There also may be a filter where the line goes into the carburetor,
but I don't understand the fitting there. There's a large part that screws into
the carb, and then a smaller part behind it which the line goes into. I don't
know if I should hold the smaller part and loosen the large part, or try to undo
both at once. When I turned it a little the small part turned with the large
part. I tried holding the small part and putting some pressure on the large part
to see if they would break loose, but didn't want to put too much pressure on it
before trying to find out how it goes together. Here is a photo of what I'm
trying to describe:

IMG_0631.jpg Photo by sazzyazz | Photobucket

Is there another fuel filter in there?

I don't think it just needs the idle speed increased with the set screw because
that might make it idle too fast to go in gear. Does anyone know what I should
try to do? Maybe new spark plugs because it has been a while...could that be the
real problem? It doesn't sound like it's skipping to me but I don't know. Like I
said I'm no mechanic.

Thank you for any help with this!
glug

fuel problem with straight 4 Mercruiser I/O
 

On Sun, 17 Nov 2013 16:52:55 -0500, glug@. wrote:

Hi,

I've got a straight four cylinder Mercruiser some info led me to believe is a
470 2bbl. 1976-1979, though other info told me it's a 140 hp 1973 Vega. I don't
know what to think about all that, and I'm sure no mechanic. Anyway, since the
weather has gotten cooler it no longer will idle, though the temperature may
have nothing to do with it. I'm in GA around Atlanta so it's not very cold. It
has a clear inline fuel filter that got real dirty so I changed it, but it still
won't idle. There also may be a filter where the line goes into the carburetor,
but I don't understand the fitting there. There's a large part that screws into
the carb, and then a smaller part behind it which the line goes into. I don't
know if I should hold the smaller part and loosen the large part, or try to undo
both at once. When I turned it a little the small part turned with the large
part. I tried holding the small part and putting some pressure on the large part
to see if they would break loose, but didn't want to put too much pressure on it
before trying to find out how it goes together. Here is a photo of what I'm
trying to describe:

IMG_0631.jpg Photo by sazzyazz | Photobucket

Is there another fuel filter in there?

I don't think it just needs the idle speed increased with the set screw because
that might make it idle too fast to go in gear. Does anyone know what I should
try to do? Maybe new spark plugs because it has been a while...could that be the
real problem? It doesn't sound like it's skipping to me but I don't know. Like I
said I'm no mechanic.

Thank you for any help with this!
glug

Your picture didn't come through. Get the URL of the photo in Photobucket and post it. What year is
the boat? That might be an indicator of the year of the engine. If it's a four cylinder, it's
probably not a '470', if that's supposed to be horsepower. You say it won't idle, but then say you
don't want to make it idle faster. If this engine is 35 years old, or thereabouts, and the inline
filter was filthy, then maybe the carb is a little gunked up also. New spark plugs can't hurt. I
changed mine every year when I had a Mercruiser stern drive.

John H. -- Hope you're having a great day!

fuel problem with straight 4 Mercruiser I/O
 

John H wrote:
On Sun, 17 Nov 2013 16:52:55 -0500, glug@. wrote:

Hi,

I've got a straight four cylinder Mercruiser some info led me to believe is a
470 2bbl. 1976-1979, though other info told me it's a 140 hp 1973 Vega. I don't
know what to think about all that, and I'm sure no mechanic. Anyway, since the
weather has gotten cooler it no longer will idle, though the temperature may
have nothing to do with it. I'm in GA around Atlanta so it's not very cold. It
has a clear inline fuel filter that got real dirty so I changed it, but it still
won't idle. There also may be a filter where the line goes into the carburetor,
but I don't understand the fitting there. There's a large part that screws into
the carb, and then a smaller part behind it which the line goes into. I don't
know if I should hold the smaller part and loosen the large part, or try to undo
both at once. When I turned it a little the small part turned with the large
part. I tried holding the small part and putting some pressure on the large part
to see if they would break loose, but didn't want to put too much pressure on it
before trying to find out how it goes together. Here is a photo of what I'm
trying to describe:

IMG_0631.jpg Photo by sazzyazz | Photobucket

Is there another fuel filter in there?

I don't think it just needs the idle speed increased with the set screw because
that might make it idle too fast to go in gear. Does anyone know what I should
try to do? Maybe new spark plugs because it has been a while...could that be the
real problem? It doesn't sound like it's skipping to me but I don't know. Like I
said I'm no mechanic.

Thank you for any help with this!
glug

Your picture didn't come through. Get the URL of the photo in Photobucket
and post it. What year is
the boat? That might be an indicator of the year of the engine. If it's a
four cylinder, it's
probably not a '470', if that's supposed to be horsepower. You say it
won't idle, but then say you
don't want to make it idle faster. If this engine is 35 years old, or
thereabouts, and the inline
filter was filthy, then maybe the carb is a little gunked up also. New
spark plugs can't hurt. I
changed mine every year when I had a Mercruiser stern drive.

John H. -- Hope you're having a great day!

I would also check the choke setting.