Those systems are electronically controlled so I doubt there's any way you can change it & if there is you can bet it won't be cheap. Messing with the sensors etc is never a good idea unless you know exactly what your doing. I'd leave it alone if it was my motor. If you want to smooth it out to use it for trolling then perhaps figuring a way to mount a smaller motor on your tube might be a better idea.

Mercury screwed you over and there isnt much that you could do to make it run on 4 pots the whole time. Heres how the 2 + 2 mercury system works....... two of the four carburettors have no idle jets (but have small orifices for oiling purposes)therefore when speed (read air flow through carb venturis) lowers to point where high speed jets no longer pick up fuel, that cyl just cuts out. At idle it is a two cyl engine and when speed increases to point where high speed jets take over the engine runs as a four cyl. Simple system.... one suggestion would be to replace the carbs which have no idle jets with 2 that do have the idle jets or add idle jets to existing carbs...... Either way its a bit of a root around!!

I have 2 x merc 135 optimax and getting the hang how those engines operate is a pain in the ass too!!! good learning experience tho!

thats very helpful thanks. what was mercury thinking. but anyway will put up with it.

after some thought, it wouldnt really be that hard to change the carbies..... if you want to go down that way let me know and I can give you some more tips and stuff about adjusting linkages ect!!

cheers bud!