Yamaha Oil Injection

I just purchased a 1994 150hp Yamaha Saltwater Series outboard. ($1800 including controls) (Model TXRS) 120 compression across all 6 cylinders, lower unit seals good, good spark, very clean. All and all seems to be a good motor. I have not run the the motor as it was not an option at the location of purchase. Back in my garage I have removed the cabs for cleaning/rebuilding and noticed that the link rod from the carb linkage to the oil injection pump has been removed. I assume the previous owner must have pre-mixed the fuel and that removing the link rod must disable the oil injection. I wish to use the oil injection option on this motor and have read that I can run it at an idle with pre-mixed fuel and check the flow of the oil injection. Does anyone have some instructions to test the oil injector pump? If the oil pump is good, I will purchase a link rod and re connect it. If the pump is bad I will save the $46 for the link rod and just pre mix the fuel. I have a Yamaha ox66 200hp on my other boat and never had any issues with the oil injection. I suspect this thread may draw out skeptics of oil injection. Thanks for any input.

Re: Yamaha Oil Injection

Removing the rod doesn't disable the pump. Only allows it to go into full flow. While running it on premix, pull one of the oil lines off the intake and see if oil is moving up and out the tube.

Re: Yamaha Oil Injection

That is what I suspected. In theory if the rod was left off would the motor run correctly? Would it foul the plugs or have other adverse effects. I am going to replace the rod but I am trying to piece together why it would be off the motor. Is there a benefit or a common reason for this? Could the previous owner have been running it this way with out causing damage to the motor?

Re: Yamaha Oil Injection

they normally remove the oil pump drive shaft when disabling the system.
you need to talk to previous owner or start looking and testing

motor would be using way too much oil at lower RPMs with that linkage missing if pump was functioning

Re: Yamaha Oil Injection

I removed the pump to find as you suggested. The pump drive shaft has been removed. I used my drill to rotate the pump shaft and the pump seems to work. Should I purchase a pump drive shaft and linkage and restore the oil injection or would it be best for the motor to just pre mix the fuel? If I go with pre-mix, will the motor run without the external oil tank hooked up or does the tank and wiring need to stay intact?