Disabled VRO Question?

[CaptainPuget]

I have a 1987 Johnson 110hp that has had its VRO system disabled. The engine is running fine at mid and high speed. Actually it runs OK at low speed as well but it just seems to run "dirty" at low speed. By that I mean it smokes, the exhaust smells of unburned fuel and it leaves a sheen of oil on top of the water at idle. The plugs are always black and wet when I check them. I have rebuilt the carbs and changed the thermostats and checked that it is running at the correct temperature. No help. There is no low speed adjustment on the carbs so I cannot lean it out at idle.<br /><br />Could this condition be a result of running 50 to 1 fuel/oil mixture in a machine that was designed for something around 150 to 1 at idle speeds? If so is there something that can be done to the carbs to compensate? Has anyone else experienced something similar on a disabled VRO system?

 

[Kenny Bush]

Re: Disabled VRO Question?

Don't know if I can help, but I have the same condition too. It seems to work for me to lean the oil a little at maybe 60:1 . I have been told that oil injection systems use much less oil than premix. That is probably why they are loading up at idle. I have gotten used to the smoke, and with oil leaned out a little, I have had several hundred hours of use with no problems.

 

[CaptainPuget]

Re: Disabled VRO Question?

Thanks for the response BC. I don't know that I could cut back on my oil without worrying about it when I'm at higher RPMs. I can get used to the smoke. It's not a big issue.

 

[lakeman1999]

Re: Disabled VRO Question?

My understanding is that they (vro) use less oil only at slow speed, and it varies to a 50/1 at wot. If this is the case, instead of using 60/1 all of the time (and short lubing at wot), and as most motors are mostly run fast I think it is better too pre mix at 50/1 and just get extra lub for the minimum hours at slow speed, but have adequate (50/1) lube for most of the run time which in majority of motors is faster speeds.