Mercury 150hp fuel mix bypass or remove

[bottlenose]

"If planning to mix oil/fuel y

"If planning to mix oil/fuel yourself, I have heard that one should not just bypass the auto mix system, but "remove it" and put a "now available" plate over pump hole. This was to keep "parts" from wearing out and dropping in engine and seizing it up. What is the thoughts on this please??"

 

[galamb]

"Randall, personally I would n

"Randall, personally I would not remove a functioning oil injection system.

Although they get blamed for everything from an overheat to running a boat aground, they almost NEVER are the cause of an engine problem.

Anyhow, if you sleep better at night mixing your own gas then you have two choices.

Remove it all together, that way there is nothing to break and possibly cause another issue - I believe Merc sells a plate to cover the hole where the pump was "or" pull the pump and remove the drive gear then remount the pump - save the gear incase some future owner wants to restore it,

Bypass it. But if you do that I would run a piece of oil hose (and fill it with oil) from the input to the output nipples on the oil pump. That way it will pump itself in a circle, functioning as it should, just not sending the oil anywhere...."

 

[bobbyc]

"If your oil tank is under the

"If your oil tank is under the cowl, another, easily reversible way of doing this would be to remove the oil line and check valve from the fuel line and plug the opening in the fuel line. Get a piece of tygon tubing and connect it to the check valve. Run that tubing into the top of the existing oil tank through the vent or the fill opening. You now have a closed loop system, the oil pump is fed by the reservoir and pumps the oil back in to the reservoir. Mix your fuel at 50 to 1 and see if you like the results. If you don't, restoring the oil injection is a 2 minute operation. If the results are what you want, you could drill a hole in the top of the oil tank to permanently and neatly run the oil hose. My concern about using the short hose loop to keep the pump lubricated is that if the pump had any internal leakage, it might eventually run dry and seize. Using the existing oil tank provides a large reservoir should there be any leakage. Some dis-advantages of running 50 to 1 include a rich oil mixture at low rpm when the injection system would have been providing a 100 to 1 reduced mixture and the problem of getting rid of the premixed gas at the end of the season."