I have a 1999 yamaha outboard that goes for about 5 minutes and the alarm goes off. I wait 15 seconds idling and can go again.<br /><br />No obstruction visible to show overheating-- although I do see steam around motor when stopping-- assume this is normal from running.<br /><br />This has oil injection-- and I see a small air gap about 1 inch in the line. Could this be preventing flow of oil to system and causing it to shut down? The oil level is where it should be. <br /><br />Should I simply try to add some oil to line to remove the air gap? <br /><br />Any other suggestions?<br /><br />Thanks,<br /><br />ET<br /><br />Details on motor:<br /><br />Yamaha 6h4 40 ELRY L8439T5<br /><br />40 hp 2 stroke motor with Oil injection--