Rough Idle and sounds to quiet!

Recently purchased a used boat with 2000 Johnson 90HP V4. It ran great for a couple of months but now runs rough at low rpms and has reduced torque and sounds like its running rich but without all the smoke you would expect. When out of the water, the engine is very quiet and it use to be very loud. While at idle (out of the water) I unplugged each of the plug wires. Neither of the ones on the port side made any difference. Both of the ones on the starboard side caused the engine to stall. Shouldn't all the plug wires have the same effect or is this normal? It sounds like there is a low speed coil issue but I'm not well versed on this engine. Any ideas?

Re: Rough Idle and sounds to quiet!

Slow Ride said:

While at idle (out of the water) I unplugged each of the plug wires. Neither of the ones on the port side made any difference. Both of the ones on the starboard side caused the engine to stall.

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You're running on 2 cylinders. You need to check spark on the dead cylinders. If spark, then carb needs cleaning.

Re: Rough Idle and sounds to quiet!

Ok, I pulled the plugs out and put them in the plug wires. I cranked it up and no spark on the plugs and no gas coming out of the hole in the cylinder either? When out of the water the motor is slow to build RPMs. If I open the throttle wide open, it takes 3-4 seconds for the rpms to get to 5500. So, I put it all back to gether and went to the water. I put it in the water and as ussual it ran rough at idle. When I push the throttle to wide open, the RPMs come up slowly for about a half a second and then "BAM!" IT takes off like a rocket and runs like nothing is wrong! I never noticed this before but it could have been this way all along, although I'm sure it was louder out of the water in the past. Is it possible that it sinces the torque load and turns the two cylinders on and then back off when not needed? It is an Optical Ignition System. Does this make a difference?