Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 119Get this manual
56789 Disconnect PURPLE bullet connector lead of enrichment valve and touch MALE end (c) to GROUNDRemove one outlet hose from enrichment valve and place container under valveSqueeze primer bulb until firmTurn ignition key to position and push IN on key
While holding key IN, enrichment valve should click and fuel drain from exposed port
10If valve does not clickreplace valve