78 85 merc poor throttle

[jimmy57]

got a friend whose 85 merc will not throttle up normally he has to slowly work the throttle forward from idle or it dies. it will idle ok and run fine at wot i told him to check carbs and readjust idle mixture screws what do you think on the right track?

 

[emckelvy]

Re: 78 85 merc poor throttle

Yup. Sounds like a classic problem of too-lean idle mixture. Have him adjust 1/8 turn CCW (rich) on each screw until it responds cleanly at throttle tip-in from idle.

BTW the best way to get the mixture "tweaked-in" is in the water, warmed-up to normal operating temp, idling in gear.

Adjust each idle mix needle until the engine idles smoothly; note the adjustment range, lean-to-rich, and set the needles to the "slightly rich" side of the middle of the range. Then you can begin the fine-tuning of 1/8 turn at-a-time to get it just right.

If you can't find a range where it'll accelerate properly, you may have other issues but the idle mix is a good place to start.

HTH.........ed

 

[jimmy57]

Re: 78 85 merc poor throttle

thanks i was thinking that was the place to start i will let him know and when i find out will post the results thanks again

 

[jimmy57]

Re: 78 85 merc poor throttle

we found bad wires on the trigger assy.replaced the trigger and it improved greatly