Suzuki DF200/DF225/DF250 V6 4-Stroke Outboards Service Manual, Page 38Get this manual
PERIODIC MAINTENANCE
GEAR OIL
Change initially after 20 hours (1 month) and every 100 hours (6 months)1Place outboard motor upright on level surface2Place container under the lower unit3Remove lower gear oil drain plug first, then remove gear oil level plug and drain gear oil