Oil Injection for Johnson 200hp Venom

[Jetcrusr69]

I was told to do away with my oil injection system due to the fact that they are unreliable. Does this hold any water? Thanks Brian

 

[rons boat]

Re: Oil Injection for Johnson 200hp Venom

Absolutely, why take a change when nobody yet has devised a perfect system that injects properly all the time. Why take a chance? See other posts for technical discussion.

 

[jegervais]

Re: Oil Injection for Johnson 200hp Venom

Nope, not a drop.<br /><br />The VRO is both a fuel pump and an oil pump - it is operated by an air motor which uses a diaphragm and rectifier valves to convert crankcase pressure and vacuum pulses into motion for the pump's 2 chambers. The most common failure in a VRO is the air motor diaphragm, when it fails, the pump doesn't work - period. It won't pump fuel or oil and the motor doesn't run - a motor that can't run, won't blow up. The unit can and will pump water. Although it has a "no oil delivery" alarm it cannot tell what it is pumping. In fact, its still the only oil injection system on the market that features a "no oil" alarm. Therefore, checking the oil reservoir for water intrusion occassionally is a good idea.<br /><br />The other failure I've seen is the seal on the oil piston - when it goes it usually causes the unit to over oil. It can, if damaged badly enough cause fuel to get into the oil tank, but it is pretty rare. The VRO has a bad "rap" with alot of boaters due to inexperienced or unschooled "mechanics" who can't find a reason for a powerhead failure and point their finger at the pump. I've owned VRO equipped Johnson's since 1991 - although I've since sold them, I know the owners and they're still running fine. I only know of 2 bonified VRO failures we serviced at my last dealership in the last 5 years. <br /><br />In my opinion, that's pretty reliable. If you ever hear someone say "My V-6 engine blew 2 cylinders, the mechanic said the VRO failed..." Thats a physical impossibility - the pump mixes fuel and oil and sends that mix to all the carbs. It cannot selectively oil (or not oil) 1 or more cylinders - whoever says that should find a new mechanic.<br /><br />Search for some facts under "VRO" or "Oil Injection" or by my "member number". There are alot of mis-informed opinions out there & its hard to sort it all out some times...<br /><br />-John

 

[rons boat]

Re: Oil Injection for Johnson 200hp Venom

John, since you worked at a dealership maybe you haven't seen many fail. I don't want to do anything but see the systems improved. I have taken several VROs off motors just out of warranty and they sure look like no oil to me. You pointed out that the combination pump would if it loses a diagram stop pumping both fuel and oil simultaneously. The volume of space between the mixing connectors and the fuel bowls alone would let the engine run for a while on straight gas. Just for discussion lets say the motor is on a party barge and the fuel tank is well above the level of the fuel bowls and the tank has a lot of vapor pressure from the heat. Maybe that is what happened to the one I am working on now. Could it be that the fuel contiues to flow thru gravity, but no oil? This one happens to be a 50 Johnson installed on a Grumman Party barge. I pronouced the engine dead due to oil starvation. We rebored both cycl .040 over with new pistons, so no second chance. The motor is very low hours although not in Warranty. Did the horn sound indicating oil starvation? I will never know but it still died. I respect your experience but I could not recommend he continue his VRO operation when for sure he will get oil if he premixes. Maybe he, the owner, is just like most people and doesn't do a complete check of the Components of his VRO system or maybe he puts the cover on wrong and stuffs something together and pinches the oil hose, or the oil check valve fails. Maybe I am just not good at autopsies. But it all comes back to Murphys law. After I get this guy back in service I will promise to see if I can find what went wrong if anything in the pump instead of throwing them away like I usually do.

 

[jegervais]

Re: Oil Injection for Johnson 200hp Venom

Ron-<br /><br />Just to be perfectly clear, I didn't say they never fail. It's just extremely rare in my book. After all its a mechanical device, made by a human being...<br /><br />You didn't say what year the 50 Johnson your putting back together is, but if it is somewhere between 1998 & 2001, those were the worst years for OMC quality problems and those problems did effect the the VRO/OMS too.<br /><br />Besides the oil volume (consumption) test done on a running motor and the 2 static tests (pump removed from motor), there is one other test you can perform, if you're interested, I'll dig thru my stuff and get you the details. Let me know.<br /><br />Since the little 50 is on a Party Barge, I might suspect the thing either was over heated or could be over-propped, which could also, if run hard enough make the failure appear to be oil related. <br /><br />My first suggestion on any suspected oil failure is to take a sample of fuel from the carburetor bowls. Make sure there's oil (in the mix) and no signs of water. You can also take a sample from the boats fuel tank and the oil tank. Make your own 50:1 mix with these samples and compare with what you took from the carbs. While not scientific, it will give you an idea if the thing was supplying oil. If you've never looked at this kind of thing before the tear-down process, add it to your autopsy check list.<br /><br />Later,<br /><br />-John

 

[rons boat]

Re: Oil Injection for Johnson 200hp Venom

John: It's a 93 and I did not get to see the fuel bowls as the guy put another motor on the boat to finish the season. He folded all the cables and plugs back and used temporary controls that came with an older (1976), same size motor. The oil supply is still almost full and does not contain water. He laid the motor to the side and I went after it. It looks new and of course it now has a total rebuild. The prop was a 15pitch and the old 50 Johnson that is still on the boat (1978) does a fine job and is not overloaded. He only wants the newer (93) for the tilt and trim. That old Johnson obviously was rebuilt by somebody that knew what they were doing as it has excellent compression and runs like a sewing machine, somebody had also converted it from electric shift. I ran the barge accross the lake to get the boat and haul it to the shop. I do this mainly as a hobby and I started in the mid 50s with a 35 Lark. I spent 5 years at the Bell System Ed Ctr in Lisle IL. Sometimes I miss your state. I,d be glad to send you a picture of my view from my house and you will see why I am here. Happy New Year....

 

[jegervais]

Re: Oil Injection for Johnson 200hp Venom

Basically, your autopsy evidence was destroyed before you started... <br /><br />How big is this party barge? If it's in the 20 foot range, a 15P may be too much prop. It might be ok for a couple of people, but 7 to 10 or more and its overpropped. You obviously know the drill, find out how its normally used. In my experience, its not uncommon for a big 'toon to need an 11P or 13P prop. Some of the biggest ones even need a 9P. <br /><br />It should be propped out to spin near the upper limit (5500) with its normal load.<br /><br />Later,<br />-John

 

[rons boat]

Re: Oil Injection for Johnson 200hp Venom

Thanks John: When I get him going again I will plug his tach in as everthing from the orginal installation is in tact. I always do a water adjustment of the carbs, so I will be checking that and making sure we send him off right. It's a very light boat and the old 50 runs pretty good at 2/3 throttle and sounds about right. Lot of people have started using smaller motors for tooling around the lake and he is fimilar with the tach. He may have a spare 13 in the boat, I'll have to check. Pass along your e-mail sometime and I'll send you a relief picture. I liked Chicago except maybe about this time of year.

 

[Sand Bass]

Re: Oil Injection for Johnson 200hp Venom

Jet, I have a 1994 Evinrude 225. I disconnected the VRO the day I bought it. I have never had a problem.

 

[Jetcrusr69]

Re: Oil Injection for Johnson 200hp Venom

Thanks sandbass. Don't you find it a pain to mix the oil and gas? What is your method of doing this? I have a 40 gallon onboard tank on my boat. Do you mix it in your boat tank, or seperately?<br /><br />Jet