I have heard a lot about removing the automatic oil injection from older motors and just using mixed gas.  The theory being that the injection system could fail, causing the motor to seize.  Is it sufficient/cost effective to just replace the oil injection as preventative maintenance?  Is there some other reason for removing the oil injection?  It seems like it would be a nice feature, but I see a lot of motors with it removed.

Repair and maintenance of VRO

This article has quite a bit of info on the system.  It makes me think it is good to leave on.

I removed mine on a 95 mercury 60hp. It's too easy to mix the gas to risk it. I have heard they go out all the time...

I have a 98 Johnson 50 with the oiler removed by the P/O.  I have always mixed when ever it was an option and prefer it.  Other boats I have had in the past would sound the alarm and it was already too late.  200 hp outboards are not cheap to fix or replace.

Only seen one Mercury style gear pump bad in 10 years of wrenching on outboards. It wasn't actually the pump itself, it was the plastic drive gear on the crank that failed.
On the other hand, the Johnson/Evinrude VRO system is known as the V ery R arely O iled system.
I hear the last version (#3?) is OK and installed one last year. It's still going, but who knows when it will fail.
If you decide to leave it on, make sure your warning horn works and check to see it's consuming oil every time out. Smoke from the engine is one way to determine consumption, but calculating fuel used to oil used is best.

Running an 00' johnson 150 on our CC with the VRO removed. I'd rather spend 3 minutes mixing fuel then have to repower due to a faulty system.

my johnson 150VRO2 has been running just fine for the last 22 years.
very reliable.
from what I have read, removing the VRO system is silly and 99% of "marine shop sees em fail all the time!" stories are
thing snot actually attributed to the system.  sort of a catch all, OH its got one of those VRO things, no wonder your motor broke down.
http://continuouswave.com/whaler/reference/VRO.html

I have the VRO system on a 1987 Johnson motor and it works great.  I wouldn't disconnect it.

I have to mix my gas. The prior owner of my '05 50HP Johnrude did a half assed VRO delete. He just plugged the oil port going into the engine from the oil tank and got rid of the oil tank. The engine would only run at a little above idle with the System Matched Tach alternating randomly between Check engine, low oil and no oil warnings and audible screeching of the buzzer. What an idiot. I installed a 48HP Special fuel pump, pulled all the VRO crap off, unplugged the VRO pump wiring harness and plugged the VRO pump pulse hose. Motor runs great now. I did not want to spend the $$$ for a new oil tank not knowing for sure the VRO pump was still good ( It was disconnected, kinda) so I went with $90 fix. A retro fuel pump and pre mix.

Yea, I'm cheap.

Op don't trust the vro,  I bought a 60hp that had low compression on the center cylinder, a combo of a bad carb and oiler caused the cylinder to melt down,  $1,100 later it's rebuilt and runs great on premix!!!