Bought used 2.5 hp 4 stroke Merc 10+ years ago and very reliable first 8+ yrs on day sailer. Infrequently used. Great shape today, but dead. Started, but raced after 2 yrs of neglect and a quick carb clean. More neglect. With help of youtube and blogs, disassembled carb and soaked in carb cleaner overnite. Re-installed w/ new plug. No joy. Not even a cough. Checked spark at plug gap, visible spark, but may have been weak so I gapped a bit less (030 vs 035) and sprayed starting ether straight into carb with choke and throttle wide open. Closed both and still got no cough or anything when cord pulled. Repeated several times. No joy. Now I'm totally stumped and looking for ideas. Probably not worth paying to service? .
