Mercruiser 165 Inline 6 automotive Parts? and engine bogging

BigBowy

Cadet
Joined
Jun 27, 2011
Messages
8
Hi all. First post.

My friend just got a 72 newman deville.

The engine is the 165hp mercruiser inline 6 (GM).

I have a feeling that alot of these parts are incorrect and was wondering if any of you had any opinions on them.

The carb is a Rochester 2gc #7028140 with one vaccume port under the fuel inlet and another port on the adjacent side with a hose going to the valve cover.

The little one under the fuel inlet goes to the vacuum advance on the Delco Remy distributor.

I don't think this is a marine distributor. It is electronic ignition with vacuum advance.

Next in line is the fuel pump. Its a Carter with the bowl on top (filter inside), but it only has two line hookups. ( I think there is supposed to be a 3rd going to the carburetor).

I rebuilt the carb because the boat kept bogging down and dying (only when in gear under a load). Thought I had it working because the boat ran great on the trailer with earmuffs on so we took it out, and it started and ran just fine (fast idle and everything), but as soon as we take off, the boat bogs down and dies. I can keep it running by spraying carb cleaner (intermittent) close to the flame arrester so I know that it isn't getting fuel when the problem is occuring.

I took out the fuel tank and cleaned it and blew through the suction tube and it was clean. Also, if I remove the line off the fuel pump, gas flows freely from the line. (no syphen valve i assume) indicating that there is no blockage from the fuel tank to the fuel pump.

Keep in mind it ran great on the trailer, i had the shift linkage unhooked and was running the throttle at the carb and the motor responded as it should and sounded great.

HELP!

any thoughts? suggestions?

here are some pictures.
Here are some pictures.
 

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BigBowy

Cadet
Joined
Jun 27, 2011
Messages
8
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

So I guess What I'm asking is:

1. Is this thing going to explode?
2. Why do you think it runs/sounds good until you try to get moving?

by the way, I'm aware of the Gear change engine kill switch. (its unhooked right now because it was malfunctioning anyways.

Any help would be much appreciated.

thanks
 

RogersJetboat454

Commander
Joined
Jul 9, 2010
Messages
2,964
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

So I guess What I'm asking is:

1. Is this thing going to explode?
2. Why do you think it runs/sounds good until you try to get moving?

by the way, I'm aware of the Gear change engine kill switch. (its unhooked right now because it was malfunctioning anyways.

Any help would be much appreciated.

thanks

Welcome to Iboats.

First blaring explosion risk; The H.E.I. distributor. No it does not belong on a marine engine. You need to find a replacement.

Carb; May or may not be an auto piece. One of the old salts on here should be able to tell you.

Fuel pump; Looks marine to me. Older pumps didn't always have the vent to the flame arrestor. Again, one of the old salts could probably tell you definitively.
 

kilowatts

Petty Officer 1st Class
Joined
Apr 3, 2009
Messages
299
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

Hi Guys:

Looks to me like you have the wrong distributor but right fuel pump and carburetor. All the parts are readily available new from iboats or Napa and used online. There should be a plugged hole in back of the carburetor and in the base of the fuel pump. Insert the correct fitting and run a clear tube from one to the other so that if the fuel pump diaphragm fails you won't get a pool of gas in the bilge.

As to the running problem: check the entire fuel line piece by piece and follow the tips in the "sticky" at the start of this forum.

kilowatts
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

Don't laugh, but the pic of the distributor only shows five plug wires.
 

BigBowy

Cadet
Joined
Jun 27, 2011
Messages
8
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

Don't laugh, but the pic of the distributor only shows five plug wires.


The plug wires are disconnected at the moment because I was running a compression test. Thanks for noticing though. :)
 

BigBowy

Cadet
Joined
Jun 27, 2011
Messages
8
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

There should be a plugged hole in back of the carburetor and in the base of the fuel pump. Insert the correct fitting and run a clear tube from one to the other so that if the fuel pump diaphragm fails you won't get a pool of gas in the bilge.

Thanks for the reply. There is No extra hole on the back of the distributor, and there is No other ports on the fuel pump besides the two that are hooked up. I've had the pump off and examined it very closely. This is part of my concern. I didn't know if the early ones just didn't come equipped with these or what.

You say you can buy stuff on here? I'll check it out.

Thanks...
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

The plug wires are disconnected at the moment because I was running a compression test. Thanks for noticing though. :)

Sometimes it's the simple thing. You'll get it worked out.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,092
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

check the bottom of the fuel pump for the fitting, maybe it`s plugged and thats why fuel delivery is a problem
 

BigBowy

Cadet
Joined
Jun 27, 2011
Messages
8
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

thanks, there is no port on the bottom of the fuel pump.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,092
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

The must be a threaded port for the vent line fitting to the carb(marine unit)
Then look for a small 3/32 hole in the bottom (auto version)
the hole /vent tube serve a purpose. It allows the diaphram to move up and down .sucking in and expelling air. Marine unit has a tube to visually see a ruptured diaphram and direct the fuel to the carb body. Auto dosent have this, only a hole to dump the fuel into your bilge.
 

BigBowy

Cadet
Joined
Jun 27, 2011
Messages
8
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

Ok, I will take the pump off and look at it again. Thanks for the help.
 

RogersJetboat454

Commander
Joined
Jul 9, 2010
Messages
2,964
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

The must be a threaded port for the vent line fitting to the carb(marine unit)
Then look for a small 3/32 hole in the bottom (auto version)
the hole /vent tube serve a purpose. It allows the diaphram to move up and down .sucking in and expelling air. Marine unit has a tube to visually see a ruptured diaphram and direct the fuel to the carb body. Auto dosent have this, only a hole to dump the fuel into your bilge.

Bt,
How sure are you that marine fuel pumps had this in '72? My Volvo which would be a '72-'73 production date has absolutely squat on the factory fuel pump to vent the diaphragm.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

How sure are you that marine fuel pumps had this in '72?
imho. they didn't... look at s/m 1 and 2. neither refer to a 3rd line going up to the carb. in s/m #3 it does. so in my mind. the marine fuel pump wasn't in place till '78 where s/m 3 refers to the third fuel line..

i'll also confirm this by saying i'm on my second 165 L6. one a '72, the other a '75. both have the same fuel pump, both only have in and out.

not saying it's not a good idea to replace the fuel pump with a more modern one. sierra has a modern replacement with three line.. one to go up to the carb. for fuel dump in case the diaphram ruptures.

but from the oem, up to where s/m 3 is in place. i don't think they came with the 3rd line.
 

Fordiesel69

Lieutenant Junior Grade
Joined
Sep 18, 2009
Messages
1,146
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

It will not have that line. My 120 4cyl and my current 77' 165 inline 6 doesnt either. When the diaphram rips, it will flood the oil with fuel and/or flood your bilge with fuel.

As for it not accelerating, it could be weak fuel flow, or something internal to the carb. I suggest hooking a hose from a aux gas can, direct to the fuel pump. That will rule out a fuel tank / line problem.

BTW it is best to replace the line from the carb to the fuel pump with metal. Instead of rubber.
 

BigBowy

Cadet
Joined
Jun 27, 2011
Messages
8
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

Thanks for all the replies guys. I confirmed with a mechanic today that some of the early fuel pumps did not have the 3rd line. However the distributor is wrong. My problem is def a fuel issue. I will use an aux fuel source and go from there.

Too bad the distributors are $600.
 

BigBowy

Cadet
Joined
Jun 27, 2011
Messages
8
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

Good news all...I found two cracked spark plugs and replaced all the plugs. Then I took my time adjusting the air mixture screws on the carb at the boat ramp (while on trailer). Took it out and drove it for an hour ran like a champ. Thanks for all the help. I just need to get my friend to fork out the cash for the proper distributor so we don't blow up! Oh, and getting some seats in it would be nice. lol.

Thanks again.
 

sandersps

Petty Officer 2nd Class
Joined
Mar 14, 2010
Messages
104
Re: Mercruiser 165 Inline 6 automotive Parts? and engine bogging

I was going to suggest that the vaccum advance was causing the bogging, But you got it fixed already. Maybe next time
 
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