1993 90hp merc misses at idle/while reving after service

[3car]

Recently aquired boat. At first it wouldnt hold a decent idle without almost continuously pumping the primer bulb, but it ran pretty well at speed. However, it would only run to 4500 rpm with the correct pitch prop.

Heres what I did today:
-New primer bulb
-New water seperator
-new fuel filter(under cowl)
-disassembled and cleaned carbs
-installed fuel pump diaphram kit
-new spark plugs

I am pretty certain I didn't mess anything up with the carb kits and diaphram kit.

The primer bulb is now staying hard. It fires right up and will idle in the tank without throttle, but it has a serious miss which gets worse when you apply throttle. Removing the plug wires one at a time has the same effect for each of the 3 cylinders.

Any ideas?

 

[j_martin]

Re: 1993 90hp merc misses at idle/while reving after service

I used to train IBM field engineers. The hardest thing to teach them was this:

If you walk up to a running machine, do something to it, and it now does not run, WHAT YA DID TO IT BROKE IT.

You need to retrace your steps before you proceed.

If you didn't put new gaskets in the carbs, that's where I'd look first.

hope it helps
John