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MCM 170 Mercruiser 1986 backfires

"did you verify the check valv

"did you verify the check valve in the accelerator pump was working?

Also, did you check the power valve operation?

did you adjust the accel pump rod to spec'd length (height)?"
 
"As far as I can tell the chec

"As far as I can tell the check valve is working, I replaced it in the carb rebuild. It is the ball bearing, spring, and "T" retainer correct?
I replaced the power valve also when I rebuilt the carb.
I did not see any type of adjustment on the accel pump rod? The rod was the straight version and it had one hole for mounting. Is the something I overlooked?"
 
"replacing the check valve doe

"replacing the check valve doesn't mean its working. a leaking check valve will limit the pump shot when needed. You can test it with carb cleaner while apart.

The pump rod is a 'bend to adjust' type. The measurement is in the service manual and i don't have access to a 4 cyl book for the mid-80's. I remember the reference point at the flame arrestor flange...maybe one of the other posters can help with the other point and the dimension. If it is off a lot, it, too, can make the pump shot a bit short."
 
"The accelerator pump is strai

"The accelerator pump is straight, not the one with the 90 degree bend? If anyone has the specs and illustrations from a service manual please let me know."
 
"it is the 2 barrel Mer-Carb,

"it is the 2 barrel Mer-Carb, right?

if yes, the accel pump rod is the one that's on the "left" of your picture."
 
Yes it is a 2 barrel and I do

Yes it is a 2 barrel and I do know where it is and what it is. I was just wondering if anyone has instructions and illustrations on how to adjust it.
 
How to check the pump rod adj.

How to check the pump rod adj. per SELOC:

Back out the idle stop screw all the way. Completely close the throttles and lay the pump gauge across the top of the carb air horn ring with the 1-5/32" leg hanging down on top of the pump rod; it's the gauge you used to set the float. The bottom of the gauge should just touch the top of the pump rod. Carefully bend the rod to obtain the proper setting.
 
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