VRO. The Devil?

[Unclebob]

So, I have a 1999 Johnson 200 on my AS 215 Explorer project. Engine has been sitting for a few years. Havent had a chance to mess with it much, but did spend an hour playing with it late yesterday.

Compression is perfect. Good Spark. Engine did not fire, so I'm assuming the carbs need rebuilt, since it had been sitting for so long.

Pulled the air box off the front of the carbs yesterday and drained the float bowls to see how bad the fuel was. Kinda surprised to see what appeared to be solid oil flowing out? Pulled the fuel inlet to VRO Pump and it had a LOT of oil in it as well. Pumped a gallon or so of fuel out and it got a little better, but not much. Isn't the fuel side of the VRU pump isolated from the oil side by a diaphram?

My VRO is all hooked up and the previous owner said he had no problems with it. But you know how previous owners are.

Gave the engine a whiff of starter fluid and she fired right up, so I know I'll be focusing on a fuel issue. I know carbs well, but have never needed to mess with a VRO pump. Heard all the horror stories.

This thread made me want to post something here, since y'all seem more of the DIY type.

http://www.thehulltruth.com/boating-for ... ave-3.html

Should I bother with getting the VRO system right? Bypass it and pre-mix?

edit: Yes, I've seen this 'Mixer Myth' document. A good one..

http://continuouswave.com/whaler/reference/VRO.html

[flounderpounder225]

So, I have a 1999 Johnson 200 on my AS 215 Explorer project. Engine has been sitting for a few years. Havent had a chance to mess with it much, but did spend an hour playing with it late yesterday.

Compression is perfect. Good Spark. Engine did not fire, so I'm assuming the carbs need rebuilt, since it had been sitting for so long.

Pulled the air box off the front of the carbs yesterday and drained the float bowls to see how bad the fuel was. Kinda surprised to see what appeared to be solid oil flowing out? Pulled the fuel inlet to VRO Pump and it had a LOT of oil in it as well. Pumped a gallon or so of fuel out and it got a little better, but not much. Isn't the fuel side of the VRU pump isolated from the oil side by a diaphram?

My VRO is all hooked up and the previous owner said he had no problems with it. But you know how previous owners are.

Gave the engine a whiff of starter fluid and she fired right up, so I know I'll be focusing on a fuel issue. I know carbs well, but have never needed to mess with a VRO pump. Heard all the horror stories.

This thread made me want to post something here, since y'all seem more of the DIY type.

http://www.thehulltruth.com/boating-for ... ave-3.html

Should I bother with getting the VRO system right? Bypass it and pre-mix?

edit: Yes, I've seen this 'Mixer Myth' document. A good one..

http://continuouswave.com/whaler/reference/VRO.html

I disagree with most who slam the VRO, it is a good system if maintained, clean the tank each year with the filter, and watch for signs of problems, like what you have, The problem I see with pre-mix on larger boats is the amount of fuel you are dealing with, with oil prices the way they are, you can really throw some $$ away mixing 50:1 into large guantities of gas.  Plus I think the gas spoils faster with the oil in it, IE sitting over the winter time.  Just my .02.

[Keith Knecht]

Hey Unclebob,

I just got a 1996 200 hp Johnson and will be removing the VRO based on the recommendations of two friends who are both certified omc mechanics.  They have a combined experience of over 60 years.  I respect their opnion.  Both have worked for many years for OMC dealers.  There must be a reason and one that I know is they mentioned a "nylon drive gear" that strips out unlike the Yamaha which has a brass gear.  Hope that helps. Saw the thred on THT and am surprised no one mentioned the nylon gear.  I thought that was pretty common knowledge among OMC mechanics.  There may be other issues as well but that is the one that I have heard.

[Unclebob]

Hey Unclebob,

I just got a 1996 200 hp Johnson and will be removing the VRO based on the recommendations of two friends who are both certified omc mechanics.  They have a combined experience of over 60 years.  I respect their opnion.  Both have worked for many years for OMC dealers.  There must be a reason and one that I know is they mentioned a "nylon drive gear" that strips out unlike the Yamaha which has a brass gear.  Hope that helps. Saw the thred on THT and am surprised no one mentioned the nylon gear.  I thought that was pretty common knowledge among OMC mechanics.  There may be other issues as well but that is the one that I have heard.

Could be that nobody mentioned a nylon drive gear, because there isn't one in an OMC engine. The VRO pump is crankcase pressure driven, like a standard low pressure fuel pump. Or were the early OMC VRO pumps different in that they were mechanically driven?

http://continuouswave.com/whaler/reference/VRO.html

Were they thinking early Mercury EFI? Regardless, still trust those mechanics? See what I mean?

[wingtime]

Yeah no nylon drive in a VRO crank case pressure driven as already mentioned.  Mercury is gear driven.  I have heard it can pump straight oil if it runs out of fuel..  This makes it a hard to winterize it by simply letting it run out of gas while running.

[Capt. Bob]

Well,
Keith bought the engine he is speaking about from me. I too disagree with the removal of the VRO system but that's his decision.

Didn't post to argue the merits either way but rather to let you know that I had the same oil intrusion over periods of no-use time. Always cleaned out the carb bowls after an extended down time and never seemed to have a problem.


I'm not a mechanic nor have I ever stayed in a Holiday Inn Express. :|

[slvrlng]

Mine was disconnected when I got the boat. When I went to pick it up from my mechanic (who was at MMI in 94 -95) he told me it was a good thing its disconnected. These motors were the main engines they used at the school at that time. Lets see that's 3 OMC techs voting for disconnect.
I have a OMC manual for my 94 175 Oceanrunner. If you would like to borrow it you are more than welcome. It has the complete breakdown and troubleshoot section for the VRO2 system. Just let me know.

[Unclebob]

Well,
Didn't post to argue the merits either way but rather to let you know that I had the same oil intrusion over periods of no-use time. Always cleaned out the carb bowls after an extended down time and never seemed to have a problem.
:|

Can you speak more on this? Boat hasnt been used for at least a year. How would float bowls fill with oil if boat wasnt used? Can the oil make it into the fuel tank?

[Unclebob]

Mine was disconnected when I got the boat. When I went to pick it up from my mechanic (who was at MMI in 94 -95) he told me it was a good thing its disconnected. These motors were the main engines they used at the school at that time. Lets see that's 3 OMC techs voting for disconnect.
I have a OMC manual for my 94 175 Oceanrunner. If you would like to borrow it you are more than welcome. It has the complete breakdown and troubleshoot section for the VRO2 system. Just let me know.

Thanks for the offer, I think I have an old OMC manual around here somewhere.

I'm not against disconnecting it, if someone can tell me why, or explain the shortcomings of the OMC VRO.

I've had many Oil Injected outboards and never had a problem with Oil Injection.  (Yamaha, Mercury, Evinrude)

Just trying to understand, because, it seems as if the 'failure mode' of OMC OIL Injection is just more oil. Plus, it alarms better than Mercury or Yamaha when it comes to Oil Problems...

[Keith Knecht]

Ok, I stand corrected.  Maybe there isn't a nylon gear that drives the pump. Thought that's what they said.  I just know that these guys have been around OMC for a long time and I respect their opnion. I also know that if Bob says he had no problems with it, I can take that to the bank.  The mechanics said to remove the vro with out the least bit of hesitation when I told them that the engine had been running on VRO and that there were no problems with it.  Do what you like.  I know that at some speeds there will be a little too much oil in with the fuel if I premix but I know that there will never be a failure due to lack of oil.  I have a good friend that has an 88 200 hp Johnson that he has been runing on premix since 1990 and it refuses to quit. Oh, by the way that motor pushes a a 222 walkaround.

[Unclebob]

I'm on the fence. If my VRO Pump is hosed, I'll disconnect that sucker and never look back before plopping down $350 for a replacement. I could use the oil tank room in the transom for a spare prop, or somewhere to hide an extra 12 pack of beer. I dont mind pre-mixing. Heck, if my tank was pre-mixed, I could run a Tee to feed my 9.8 Tohatsu Kicker I plan on mounting later..

But if it's working properly, and is as solid a system (or better) than all the other Oil Injection Outboards I've owned, I might just leave it alone..

[Keith Knecht]

Hey Unclebob,

You don't have to spend $350 to replace it as long as it's working.   There's some stuff to disconnect and block off but you don't have to spend money for a new pump without the vro.

[wingtime]

Don't you have to buy a non VRO pump to disable it?  

My understanding is that it is a dual action pump.  If you out of fuel the oil side pumps more oil into your carb bowls.  OP said he turned it over a few times and ran it on starting fluid.  So I would think that would fill the bowls up with oil....  but I didn't stay in a Holiday Inn Express either!  

[slvrlng]

Maybe this will help.

[Capt. Bob]

Well,
Didn't post to argue the merits either way but rather to let you know that I had the same oil intrusion over periods of no-use time. Always cleaned out the carb bowls after an extended down time and never seemed to have a problem.
:|

Can you speak more on this? Boat hasnt been used for at least a year. How would float bowls fill with oil if boat wasnt used? Can the oil make it into the fuel tank?

Not much, only to say that I would find what appeared to be excess oil in one or two bowls when the motor sat for a long time. I'm not qualified to say why. Keith may find the same thing when he starts working on the 96 I sold him. While it ran fine when last used, it has sat for over two years. I don't know if the oil separates from the fuel or is siphoned in (it doesn't seem right but ) so I can't add anything else to the mix.

If you plan to keep the VRO active, I would recommend changing the filter in the remote tank. I did have one clog on me but the alarm worked and I disconnected the supply line from the tank fitting and inserted directly into the tank through the fill cap. Was able to continue home. This was on my 85 115 Johnson. The 96 never cause any problem.

I'm not sure how the oil would traverse back into the fuel tank. Good question. I also sold Keith my tank but it had been drained for almost 18 months before I removed it. I hadn't noticed any oil inside but then I didn't run a camera down the fill connection.

It seems that a lot of owners remove (disable) the VRO and from various postings on boating forums OMC mechanics point to failures. Sounds like a crap shoot to me.

Good luck.