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Johnson VRO strikes again


tasksta

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Hi all

On the weekend I had my no oil alarm appear on my VRO equipped jonno 70. A little concerning considering its a new pump. Anyhow after some research it appears a leak in the fuel line can cause his well known issue. I have found multiple small leaks on the manifold after the pump feeding the carbs.

My questions are:

Are the connections supposed to be made with tie straps?

Are these garden variety cable ties?

Is there a better way to secure these?

Simple fix to replace but just want to have it done once and right. I'm really pushing to keep the VRO despite the nay Sayers but I'm very close to disconnecting it.

I know it's a can of worms but would like to know of you have disconnected your VRO?

Cheers Paul

Edited by tasksta
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I have had a 70hp and a 90 hp johnson both oil injected and had not a drama with either motor. Each motor powered the same boat for 10 yrs each. I cant even imagine the amount of hours would of been on each motor ? I think they are a great pre 4 stroke and HPDI engine.

Dave

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yes tie straps can be used , but you must have the correct strap gun to torque them.do not use garden type straps . it is recommendedthat if you change the v.r.o you run the first tank of fuel at 50 to 1 mix to safe guard against a fault in the system . also do not prime the oil to the v.r.o by hand ,after connecting the oil line ,in must draw it up it's self .another reason why you run a 50 to 1 mix .you can disconect the vro and use it as a fuel pump only,or you can fit an earlier type fuel pump and run 50 to 1 premix i hope this makes sense ,if your not sure p m me .cheers ray p.s i have done all this many times .

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Thanks for the advice guys.

I will order some proper OMC ties and the gun to fit them pproperly, that makes a lot of sense over simply using cable ties.

Pump has been in for 6 months without issue, when it let go it cost me two pistons so im a little tentative but my preference is to keep it.

Besides potentially over oiling at idle speed is there any downsides to premix?

Cheers

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Hi, you want to make sure you get the right cable ties and if they are OMC ones they will be very old. P/N 320107 are the correct cable ties and if you claim or a "mechanic" claimed the VRO was at fault for damage to two cylinders on a three cylinder engine then they do not know how the system works. If the VRO (or more correctly called the OMS) failed then ALL the cylinders will be affected because it injects oil before the carbies so if one carby does not get oil they all do not. The failure was more likely related to a lean running situation, but at the end of the day if the rebuild was done correctly and the carbies cleaned that is the main thing. What was the P/N of this new OMS?

Cheers,

Huey.

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Thanks for the part number ill make sure i get the right ones. The OMS pump diaphragm failed, whether it ran lean on oil or fuel I'm not sure.

I have the service manual and agree its a very simple system, hence why im so keen to keep it.

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Hi, what P/N was the OMS (there are old ones and newer ones-so I hope you got the latest and greatest). I can guarantee you it would not of been an oil related failure if the damage was as you described and if the diaphragm splits the engine just will not run because it can not and will not pump fuel. I sure hope you have serviced the carbies, doing all the necessary checks since otherwise it will most likely happen again. I also sure hope someone that knows what they are doing, did the mods to the cooling system too.

Cheers,

Huey.

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Do you deliberately put the fear of god into people? :)

Its been running great for six months until the no oil light last weekend. surely if carbs or cooling was an issue it would be cactus by now?

I'm out every weekend and do minimum 40l through it.

Whats the cooling mod and carb failure symptoms you refer to?

Thanks for the free advice its hard to come by.

Cheers

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Hi, sorry to scare you but I would hate to see you back to square one with something that was overlooked. The cooling mod moves the elbow from the middle of the exhaust plate to the top of the block to stop an air pocket up high and that can lead to bad results. Of course you do not say what year model you have so it could be a latter model with this done at the factory-just like topdya good companies learn things along the way and put into practice what they have discovered in the real world and then let trained/certified dealers know about these changes-you would have to have been in the marine business for a long time to know these things so most places here in Sydney would not of been around that long. As for the carbies, no real tricks but they are a preventative maintenance item that should be serviced from time to time even more so with todays fuel. Did a tech do the rebuild and if so I sure hope they checked these things and yes I would think if the engine is running good the fuel system would be working fine, but good practice to make sure they are not original parts inside them-even parts of about 10 years ago did not have to deal with ethanol and what it can do to the fuel system. Have a quick look and see if the gaskets are black or brown on the carby bowls.

Cheers,

Huey.

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Its a 2000 model 70hp. Yes all work was done by Jonno tech, HOWEVER for a number of reasons i don't go back to him anymore.

Ill check the carby gaskets tonight.

Air silencer gaskets are brown if thats any indication?

Thanks again.

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Hey Huey

The carby bowl and body gaskets are brown. Have spent the night reading the service manual on carby servicing.

Fairly confident i could take my time and do this myself if worthwhile?

Cheers

Paul

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My old motor was a VRO which had the oil pump stuff removed so it required premixing of oil and fuel. The downside I see is letting the premix fuel/oil sit for too long in the carbs it can gum them up. Oil starvation to an engine is not a good thing. Ever. If you can reliably fix the VRO pump and ensure its working, you'll be fine but if you're questioning the work or your own work, for a moment, I'd ditch it and go premix.

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Thanks Sarge.

I have a few leaks i found that are an easy fix and are know to cause issue. Ill sort them tomorrow and test again. If still no good i may have to disconnect it unfortunately.

With baby on the way my Jonno really isn't a priority for the wife!

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Hi, it leaks where, the OMS should not leak, but if the boats fuel system or the hoses going to the OMS leak, that is not good and will also cause an aerated fuel mix to go the OMS and the engine will run a lot richer-fuel/oil ratio, then need be and will smoke more-especially if you use cheap oil.

The whole VRO or as I said before more correctly termed OMS, for the a long time, is one of the least understood systems in the outboard industry and a lot of so called experts in this industry like to blame anything and everything on it and I have lost count of the times people say just connect it. It is like me going to the doctors with a sore arm and him/her not knowing how to fix it so they just say-lets cut it off-you did not need it anyway. The devise is very solid if some tips are followed and good fuel is used and I can guarantee you not many outboard failures can correctly be attributed to a failed oil injection system that none trained/experienced people like to blame it on, just like when ignition systems have a fault they like do not have the skills to diagnose the problem so they just blame the "black box"

Did you ever find the P/N of your OMS and as for rebuilding the carbies, if it has been done recently and you are confident it was done right no real need but as with anything in life it is all preventative maintenance and if you are worried, the actual parts to rebuild the carbies will be very cheap in the scheme of things.

Cheers,

Craig.

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Its leaking from the fuel manifold. I have a new one and genuine OMC tie wraps to replace tomorrow. Also found the bayonet fuel fitting on the cruisetank was loose and have replaced this with straight through take off fitting.

Hopefully it these multiple small leaks causing the no oil light. Other than that its been solid for six months and gets used once if not twice a week.

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