Check ball, spring, and retainer???

Fishingaddict88

Petty Officer 3rd Class
Joined
Jun 1, 2017
Messages
75
Hello again, I appreciate all the help from this forum so far. I do have another question though.

1988 4 cylinder 130hp 3.0 A1 Drive

I have a Mercarb 1389-9562

Upon rebuilding my carb, I discovered that under the accelerater pump it's missing the following; spring, check ball, and retainer.

Does anyone know why this might be? Did the last owner just not add them or is there some sort of bulletin that Im not finding?

To add them or no?

Thanks in advance!
 

Fishingaddict88

Petty Officer 3rd Class
Joined
Jun 1, 2017
Messages
75
It appears in my manual as only having a return spring.. no retainer or check ball in this spot.


So if that's the case, there was no return spring. Could this be the reason I've been running rich?
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,268
Not all Mercarbs used a check ball in the accelerator pump well.
Below is some info that might help guide you some should anything have been done over the years.

Overrich Acceleration ?gBog?h
on MerCarb Equipped Models MCM 120/140/2.5L/3.0L


MerCarb Flooding / Hurth Transmission Fluid

MerCarb Flooding

http://www.carburetor-blog.com/mercarb/
Check Ball Question:
The exploded view of the instructions sheet that came with my MerCarb
carburetor kit
includes a check ball and screen at the bottomof the
accelerator pump well. Mine seems to be missing ??.
Answer:
Not all Mercarbs have the check ball and screen. This type of Mercarb
will not have a hole in the bottom of the well to support a check
ball,or the screen.
What is the check ball size for the Mercarb?
Both balls are 5/32??. When one
is aluminum, put it in the bottom of the accelerator pump. The other
ball goes into the main discharge hole.
 

Fishingaddict88

Petty Officer 3rd Class
Joined
Jun 1, 2017
Messages
75
Man... you might have solved my problem with that. I literally just got done putting this carb back together but I gotta pull it back apart to check the venturi. According to this bulletin though mine is bad...

I'll report back soon!
 

Fishingaddict88

Petty Officer 3rd Class
Joined
Jun 1, 2017
Messages
75
Awesome man!! You're a lifesaver, I'm more than grateful. After your help and some research, I do in fact have the old venturi which is noted to cause acceleration bog. I've been trying to figure this out for some time now. It was driving me insane!

MUCH APPRECIATED!
 
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