1999 Volvo Penta "WT" Models Workshop Manual, Page 21Get this manual
Step 2Change Motor Oil and Oil Filter: Engine should first be operated under load until oil is thoroughly warmed upIf oil is allowed to warm up before draining, more complete draining will be accomplishedIn addition, accumulated impurities will be held in suspension by the oil and be removed during draining operation Remove motor oil by siphoning it out of oil withdrawal tubeFollow the procedure under Draining and Filling the Engine Crankcase Install new oil filter and fill crankcase with recommended oil tNotet
Vertcal drive must be submerged in water or an accessory flushing adaptor must be used while operating engine