At my wits end with this motor... Any advice before I turn it into a boat anchor?

"Rebuilt" 1974 Merc 500 50hp. Linked and synced it. Starts up. Idles a little rough. RPMs at idle with muffs and in water at about 1300-1600 -- too high. (As an odd side note, when I first started it in the watertoday, idle was quite smooth at ~800 RPMs, but would die when I put it in gear. When I got it started again, it went from idling at 800 to 1300-1600 for no apparent reason and never went back down). So....

- If I try to adjust the idle down with carb idle adjustment screws to under 1000, it dies.
- If I try to rev the throttle, it won't rev very high and almost acts like it's bogging down.
- If I put it in gear, it dies.
- If I try a hole shot, it bogs and dies.

I'm about out of options trying to get this motor to do more than idle at 1300-1600. Not much fun for the family sitting in the water going nowhere...

..."If I try to adjust the idle down with carb idle adjustment screws to under 1000, it dies."

If you're trying to slow it down by messing with the idle mixtures that's never gonna work.

I'm guessing here, but I suspect your throttle cable is mal-adjusted, holding the throttle above idle speed.

Jeff

fastjeff said:

..."If I try to adjust the idle down with carb idle adjustment screws to under 1000, it dies."

If you're trying to slow it down by messing with the idle mixtures that's never gonna work.

I'm guessing here, but I suspect your throttle cable is mal-adjusted, holding the throttle above idle speed

Jeff

Click to expand...

You may be right.