How do I convert an oil injected outboard to a pre-mix system?

Question

I have a 200hp Mariner o/b circa 1987 with an oil injection system. This came with a boat I resurrected from the graveyard, and while it seems to run pretty well, the horn sounds sporadically and gives me reason to question the integrity of the oil injection system. I also have a 15hp Mariner "kicker" motor that I plan on installing which is not oil injected. To run both motors as they are would require separate fuel tanks, but if I convert to all premix then I could just "Y" off the existing 115 gallon fuel tank right?

Has anyone done this and am I thinking correctly? Does anyone have a better alternative? Can I just disconnect and plug the oil line and disconnect the warning system or do I need a different fuel pump?

RMSBuffalo

Answer 1

>>>Can I just disconnect and plug the oil line and disconnect the warning system or do I need a different fuel pump?<<<

You have answered your own question. That is what I would do. I would use two primer bulbs though, one for each motor. They will act as a "check valve".

Answer 2

when you convert m/cycles to run on pre-mix you increase the main jet size slightly to allow for the different fuel viscosity.  Does you injector inject into the fuel line (as it did on my old mariner - called autblend) or into the manifold on the engine side of the carb (autolube).  If it is into the manifold on the engine side then you need lager jets - if into the fuel line (or that side) then it is ok  - with 200hp I expect it is the more complex one.  Be careful some systems are quite complex indeed (e.g. http://www.dinghyandrib.co.uk/yamaha.htm...

Some more help: http://www.themarinedoctor.com/cgi-bin/Y...

And here (for 200hp with a warning about pre-mixing 200hp)http://forums.iboats.com/showthread.php?...