2009-2010 Suzuki DF70A DF80A DF90A Outboard Service Manual, Page 40Get this manual
0B-14 Maintenance and Tune-Up:
Breather Line and Fuel Line Inspection
Inspect breather line and fuel line Initially after 20 hours (1 month) and every 50 hours (3 months) Replace breather line and fuel line Every years If leakage, cracks, swelling or other damage is found, replace the breather hose andor fuel line