I have a 1999 90hp FICHT on my pontoon boat. The outboard runs fine and only has 1 minor issue. While on the lake sometimes the engine will not start right away. It may take 4-5 tries on the ignition to get it to catch. Other times it catches 1st try and no issues. I cannot figure out the rhyme or reason behind it. I pulled the spark plugs and they look good. I installed a new fuel filter about 30 days ago. Not sure what else it could be. Any help or advice would be appreciated. Thanks.