Rebuilt Mercarb, now won't hold idle..arghhh

rehgarde

Cadet
Joined
Jul 14, 2016
Messages
8
I've got a Mercury 3.0L 4cyl Mercury I/O that was stalling when backing down from running fast to a slow idle. Couple of whacks around the float sometimes helped, so I decided to rebuild the carb. (Mercarb)
Did the whole kit, cleaned out everything, replaced the float too. Reistalled everything.

Now, it will only start with the throttle all the way forward, and it takes a few seconds to catch.
Then it can back down to 1500-2000 rpm and hold there, but I can't pull the throttle back anywhere close to neutral.

Something is off that I can't quite get right. If I keep the choke valve all the way open manually, it runs better and I can bring back the rpms a little more.

Any ideas on my next troubleshooting?

I hate that I made the boat worse, and just before the big weekend to boot.

Thanks for any help you have!
Brandon
 

alldodge

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Mar 8, 2009
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43,010
I think your float level is set to high, and/or you may need to use the needle with the spring attached, a bit to much gas
 

rehgarde

Cadet
Joined
Jul 14, 2016
Messages
8
I went back and adjusted the float again. It was definitely set o drop too much. That seemed to help a little, but I can still only get it to hold at half throttle, between 100-1500 rpm. I am noticing the choke doesn't seem to be opening all the way as the engine heats up. maybe 1/2 inch total on its own. I am also getting white smoke occasionally which I never had before.
I'm pretty frustrated now, I have a feeling this is going to need more professional help.

Any other thoughts before I start dumping $$ into this boat?
Thanks
 

alldodge

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Mar 8, 2009
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43,010
also getting white smoke occasionally

Think its time to check compression. Make sure throttle is at WOT and you crank the motor at least 4 times for each cylinder
 
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