1989 Mercury 100hp 2 +2 - latest - sputters and won't go over 2000 rpm

[Str8g]

I have had 2 prior posts on this motor and have done everything i thought I could do to try to get it running right. We have gone through the ignition system and now have a new CDI stator, new mercury trigger and as of a couple days ago a new Mallory switchbox and can?t seem to figure out what to look for now. very frustrating. I have previously gone through the fuel system and the problem doesn't come from a lack of fuel, it almost seems as though it is getting two much. It is the 2+2 design and it fires and runs fine at idle but it just seems to load up upon acceleration. It would even get off on plane. We thought we had the problem figured to the switchbox because at an earlier troubleshooting session the switchbox was giving me using a DVA Multimeter a 0 volt readings at the coils on cylinders 3 and 4. so we replaced the trigger. and then stator and then switchbox. We did the rectifier test (pulled the yellow wires) from the stator with what seemed to be no change. very frustrated because it?s my father?s boat. Everything is pointing back to the fuel system now or worse. Any advice concerns or opinions would be appreciated.

 

[Str8g]

Re: 1989 Mercury 100hp 2 +2 - latest - sputters and won't go over 2000 rpm

Hopefully just a final update, but we apparently may have just resolved the problem(s) with the motor. We purchased the motor from an individual who completley rebuilt the powerhead and never had it running right. One problem we knew it had was it didn't have spark on cylinders 3 and 4. which we found ended up being a bad switchbox, but had replace the stator and trigger along the way as well. but the discovery over the weekend could prove big. a couple weeks ago I just decided to order a set of jets for the carbs just to rule out a jetting problem. I received the jets and pulled the carbs again this weekend and removed the jet from carb 1, the jet size I removed was .076 (for a 115 merc) the correct size size for the 100hp mercury is .054. all the carbs had the .076 jet. What is bizarre is the carbs on the motor are stamped W - 11 for the 4 carbs showing they were for a 100 hp mercury but the 4 float bowls had the .076 jets installed. I reinstalled the carbs and the difference was noticable in the driveway but I hope it runs well when we get it in the water this week.