Help with bog in Merc 4.3
 

Hey folks, saw a thread earlier on the topic & wondered if anyone could
help. I've had probs with the stock (carter) 4bbl carb on my Merc 4.3
The bog is really irritating. I was told to just get a "square four"
Holley and be done with it. I'm OK with this if the Holley really is a
better carb. My mechanic really wasn't able to adjust the carter that
well. One problem is finding a holley to fit. There is a Holley 600
listed for OMC/Volvo- but I dunno if it will fit my manifold.

Anyone know of a carb & an appropriate adapter for my application?
Should i just say to hell with it and go to TB fuel injection?

THANKS!

Help with bog in Merc 4.3
 

Bog us usually caused by a bad accelerator pump. They are usually
included with a rebuild kit. You just have to make sure the pump in
the kit is the right size. A friend on mine rebuilt his carb and still
had bog. I took his carb apart and found that his pump was too big in
diameter. He just squeezed it together and stuffed it in its hole. I
found him the correct size pump and the bog disappeared. An
accelerator pump simply squirts raw fuel into the carb on acceleration
to prevent bog.



wrote:
Hey folks, saw a thread earlier on the topic & wondered if anyone could
help. I've had probs with the stock (carter) 4bbl carb on my Merc 4.3
The bog is really irritating. I was told to just get a "square four"
Holley and be done with it. I'm OK with this if the Holley really is a
better carb. My mechanic really wasn't able to adjust the carter that
well. One problem is finding a holley to fit. There is a Holley 600
listed for OMC/Volvo- but I dunno if it will fit my manifold.

Anyone know of a carb & an appropriate adapter for my application?
Should i just say to hell with it and go to TB fuel injection?

THANKS!

Help with bog in Merc 4.3
 

I agree the bog is probably a carburator issue. It can also be timing
so make sure your timing is set correctly and observe it to see that it
advances as the rpm is increased. I'm not sure if the carter bolt
pattern is the same as the holley one or not. It might be. The one
bolt pattern I know is different from the holley is the gm quadrajet
with small primaries and larger secondaries. Holley does have a fairly
simply carb that is reliable and easy to fix. It is not know for it's
fuel effeciency though. The carter and quadrajet do a better job of
controlling midrange mixture. I have a 650 holley that I've had for a
number of years. The one complaint I do have is that the accelerator
pumps draw fuel from the bottom of the float bowls. If you get some
crud or water into the carb it ends up in the accelerator pump. I've
had to clean mine once because of that. All in all I would try to fix
the carb you have before buying a new one.

Eldon wrote:
Bog us usually caused by a bad accelerator pump. They are usually
included with a rebuild kit. You just have to make sure the pump in
the kit is the right size. A friend on mine rebuilt his carb and still
had bog. I took his carb apart and found that his pump was too big in
diameter. He just squeezed it together and stuffed it in its hole. I
found him the correct size pump and the bog disappeared. An
accelerator pump simply squirts raw fuel into the carb on acceleration
to prevent bog.



wrote:
Hey folks, saw a thread earlier on the topic & wondered if anyone could
help. I've had probs with the stock (carter) 4bbl carb on my Merc 4.3
The bog is really irritating. I was told to just get a "square four"
Holley and be done with it. I'm OK with this if the Holley really is a
better carb. My mechanic really wasn't able to adjust the carter that
well. One problem is finding a holley to fit. There is a Holley 600
listed for OMC/Volvo- but I dunno if it will fit my manifold.

Anyone know of a carb & an appropriate adapter for my application?
Should i just say to hell with it and go to TB fuel injection?

THANKS!