Pre-mix question

[muskrat1]

Purchased a boat with twin 1996 200 Yamaha carbed 2-strokes. (formerly oil injected)

Past owner had removed the oil injection from both engines. He ran 50:1. I plan to convert back to OI over the winter, and collecting parts now for that.

I have been running 50:1 since purchase, but do not like excess smoke at *****ing speed (900-1300 rpms), compare to my past OI motors.

Is anyone running a different mix ratio than 50:1? I know 50:1 works, just wondering how much leaner I can go, and not kill the motor at cruise 4200 rpms. Fully understand the oil injection system, works relative to RPMs.

[boats.net]

You do have to use 50:1 mix on premix.

[robert graham]

I started using the Pennzoil 100% Synthetic Outboard Motor Oil a few years ago and it definitely seems to smoke less and produce less carbon on spark plugs. I expect you could use slightly less(75:1?) for extensive *****ing and be fine. Several years ago Yamaha recommended 100:1 in some of their motors and understand it was sufficient for lubrication but not good for corrosion protection on internal shiny parts like bearings and crank area...so they returned to the 50:1 ratio. Try that synthetic oil and see what you think! Good Luck!

[BQUICK]

I would think that you could go 75:1 no problem IF you never go WOT. The oil injection system probably does a similar ratio at say 4000 rpm.

[DougBradlow]

oil injection

I decided to do the same and put the oil injection system back on my motor,but when I do does the system have to be bled or primed or is it gravity fed?If the system has to be bled or primed how is this done?I wish I never took it off in the first place and I won't mess with it again if I get the system back on and working again.I purchased a new oil pump,hoses and oil indicator light assembly.

[rodbolt17]

doug
start a new post.
include the engine model number.
include why the system, and how the system, was "disabled".