Re: 1985 30hp Johnson runs rough when butterfly in carb opens
I would start with joe reeves wot timing procedure(found here,on iboats)did mine and it worked great (fairly straight forward)
after that is completed, you will need a alligator clip and a good length of rigid wire that will fit through the clip.Put the wire through and bend it back (basically loop the wire through it).remove the throttle cable from the motor,open and close the butterfly by hand,you will see the shaft moving(between starter and outside of carb).Let the butterfly close,put the clip on that shaft(the wire should be long enough to go past the height of the fly wheel,about an inch or so).Now move the throttle arm(the arm that the throttle cable attaches to) if you look under the flywheel, you will see the cam follower(black plastic piece) there is two notches on the top side of it.The other piece that sits against the follower is the cam roller.When you advance the throttle arm,the cam roller should be in the middle of those two marks on the follower,just as the butterfly opens.That's what the clip with the wire is for,you will be more accurate by watching the wire.There should be no movement with the wire until cam roller hits those marks on cam follower(make sure the wire is sitting tight against flywheel)once the wire moves off the flywheel,that's when the butterfly is opening.If not correct adjust by adjusting screw on opposite side of carb in or out as needed.Once that is done,make sure butterfly is in right position at full throttle.Timing is 30 deg/timing mark is the embossing on starter housing(taller piece on left side).30 deg is omc spec,joe's will be different, follow his in the procedure.I hope this helps,good luck
ps,If it still sneezes a little,only at certain rpm's,trying adjusting the throttle cable adjustment(the one by the motor).just allow it to sneeze and turn the adjuster in or out until it quits.my was doing this at 1100 rpms only,so i finally just adjusted the throttle cable.haven't had problem since.
