I have a 25 hp that has been sitting in storage for 5 years. It was only run in freshwater. I bought new plugs, new gas/oil, tank and gas line. I had got it cranked and idled for 15 min. tried to recrank but took about 20 pulls. Tried crancking it over the last few days but does not sound like its even going to turn over. When I take the new plugs out they are oily and dirty looking. Could it be the carburator or fuel filter being clogged up? Any help would be appreciated! Thanks Brad