If you smell gas and one of the engine is rough and won't go to full rpm....read this.

[Riveramx]

Swap the ignition coils and spark plus from the good engine to the bad one. If the smell of fuel goes away and run smooth the problem is in either the ignition coils or the spark plugs. I don't recommend using iridium spark plugs, use OEM recommended NGK spark plugs. I had some issues with iridium spark plugs in the past. Hope this helps.