Re: orifice idle jet 40/50hp motors

One would guess because of back pressure; but I sure am no engineer. (Too bad I am not going to Yamaha school this year. One of the instructors there is a former OMC carburetor engineer.) Anyway, I can’t wait for Fleetwin to jump in on this one because it seems like there were some bulletins related to idling on those. Maybe not. I don’t have access to OMC literature anymore.

Also, in Marine Engine, did you see the commonality list when you click "more info" on those jets? (You then also have to click "show more.") There is a HUGE list of where those jets can be found on other motors. If you do run into trouble, I bet you have some of those other motors kicking around, that you could use the jets out of, as an experiment.