cnewton700
Member
Have a 84 Mercruiser 5.7L with a large Rochester 4bb. Easy to start and keep running as long as the RPM's are around 2,000 while warming up and around 1,500-1,250. I would like to get\ my idle down enough to safely drop in gear before the tuna arrive.
1. Throughout the Rpm range above it runs smooth, sounds healthy, no missing, thermostat opens at 160, water flow good from intake through exhaust with no overheating.
2. The choke plate in the primaries are perpendicular (wide open) when engine warms up.
3, The idle adjusting screw on carburetor doesn't make contact with anything so if I were to back that screw out it would only increase the space between the tip of the screw and the place it's supposed to contact.
4.A vaccum reading from the front port on the carbeurator stayed without flutuating at 23hg PSI at 1,700 rpm's.
5.The right air/fuel adjustmet screw was backed out 1 ½ turns from being closed. When I screwed it in to closed, it had no effect on the engine so I backed it out 1 ½ turns and left it as I found it. 6 The left air/fuel adjustment screw was backed out 2 turns and when I screwed it in to close, the engine dies. I also returned it to two turns out.
I just want the idle to come down to where I don't blow up my outdrive putting it in gear. Based on the info above is there something I need to do or shouldn't have done. Anything to get me going in the right direction. I would sure appreciate anyone's suggestion at this point. Thank you.
1. Throughout the Rpm range above it runs smooth, sounds healthy, no missing, thermostat opens at 160, water flow good from intake through exhaust with no overheating.
2. The choke plate in the primaries are perpendicular (wide open) when engine warms up.
3, The idle adjusting screw on carburetor doesn't make contact with anything so if I were to back that screw out it would only increase the space between the tip of the screw and the place it's supposed to contact.
4.A vaccum reading from the front port on the carbeurator stayed without flutuating at 23hg PSI at 1,700 rpm's.
5.The right air/fuel adjustmet screw was backed out 1 ½ turns from being closed. When I screwed it in to closed, it had no effect on the engine so I backed it out 1 ½ turns and left it as I found it. 6 The left air/fuel adjustment screw was backed out 2 turns and when I screwed it in to close, the engine dies. I also returned it to two turns out.
I just want the idle to come down to where I don't blow up my outdrive putting it in gear. Based on the info above is there something I need to do or shouldn't have done. Anything to get me going in the right direction. I would sure appreciate anyone's suggestion at this point. Thank you.
