Re: Gas/Oil mix for 1999 90HP
50:1 (16 oz oil to 6 gal. gas; 13 oz / 5 gal...etc. The manufacturer undoubtedly specifies use of oil specific to outboard engines - TCW3. (as opposed to oil used for 2 stroke chainsaws, etc.).<br /><br />There is good info on this in the Iboats FAQ section:<br /><br />
Iboats Oil Mix FAQ
