Carb on 78 Merc 140 HP issue

Jrezak

Recruit
Joined
Sep 16, 2009
Messages
3
Have a 78 140 ph Merc with a Rochester carb. Had some issues right after buying the boat and have done a tune up, including plugs, points, new filters, ect... Got the info from here on where to set everything and it is running now. Went to do the timing and found another problem (I think).

When I went to adjust the idle I found the bracket that holds the idle screw is loose a little. If I move it back the idle is right where is needs to be, but as soon as I throttle up and then back down it is staying at about 1100 rpms. All I have to do is move the bracket with my finger and it will go right back to about 650. I could not find any screws or bolts that hold this bracket to tighten is up. what am I missing???

Thanks,
Jeff
 

searay3

Senior Chief Petty Officer
Joined
Apr 7, 2005
Messages
655
Re: Carb on 78 Merc 140 HP issue

Pic would help. You could try removing the throttle cable from the throttle at the carb. See if the carb operates correctly without the cable. Then reset the cable with just a little tension toward the throttle stop. I have seen where the cable is slightly out of adjustment because of wear to either the cable or carb.
 
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