1986 115 Merc runs rich

[frozenokie]

For those who read the bogg out problem - the new coils/switch boxes fixed and now run 5000rpm.

After a week testing the boat, it consistently ran too rich at idle. Here are the conditions:

1. 1 3/4 turn out (vs. 1 1/2) on carbs
2. High fuel consumption
3. Holes in butterfly in carbs - someone has drilled out one of the holes in each shutter
4. BUT - runs quite well
5. Fouled out plugs after 4 days of use

I suspect the drilled out holes for the problem and making it necessary for turning out the idle screws (so it runs correctly) and the result is too rich at idle.

Am I going at this right? What do the rest of you think?

 

[frozenokie]

Re: 1986 115 Merc runs rich

UPDATE...
I went ahead and changed out the butterfly shutters. I will be testing it tomorrow and will keep yall posted...

 

[frozenokie]

Re: 1986 115 Merc runs rich

I took it out today. Apparently, the swapping of butterfly shutters worked perfectly. The idle smoothed out - still great out of the hole - less fuel consumption - and idle screws dead on at 1 1/2 turns out.