1985 Johnson 150 VRO

[stingray6724]

I have the above outboard. The VRO was disconnected when I purchased the boat 2 years ago. After $900 spent making sure there would be no breakdown on the water, then replacing the trim motor, steering cable, starter and trolling motor, and all new gauges, another problem has arisen. The motor will start easily, but only run for about 30 seconds (out of the water) unless I pump the bulb on the gas hose. I read an article that said the VRO is a pump and a vacuum. It seems to me that I have a fuel pump issue. The boat ran fine till this year, and I did have it out 2 times but could only get about 25 mph out of it at best.

Can I just completely bypass the VRO totally? If I need to rebuild the fuel pump, as I feel it is the original with no repairs performed it can only help. If someone can pass along information to purchase either a pump or a rebuild kit, with the part number and possibly a retailer, I would be very grateful. I know very little about outborad motors.

Thanks for any help.

 

[Rich976usaf]

Re: 1985 Johnson 150 VRO

read the other threads.

 

[throwback2332]

Re: 1985 Johnson 150 VRO

Hi i have a 1986 evinrude V6 150xp with VRO, I'm going to part out. 1st check the vent on your fuel tank, 2nd check the bulb, have the carbs been rebuilt and was the floats adjusted right. Also did you replace the hose from the crank case to the vro, this is the vac line that opeators the vro pump.

 

[stingray6724]

Re: 1985 Johnson 150 VRO

read the other threads.

Sorry, I was looking for helpful information, not directions that required me to read over 200 posts individually.

 

[stingray6724]

Re: 1985 Johnson 150 VRO

Hi i have a 1986 evinrude V6 150xp with VRO, I'm going to part out. 1st check the vent on your fuel tank, 2nd check the bulb, have the carbs been rebuilt and was the floats adjusted right. Also did you replace the hose from the crank case to the vro, this is the vac line that opeators the vro pump.

Thanks for the input. The carbs were rebuilt by a professional, the bulb is less than 2 years old. I take it by your reply the VRO needs to be connected and can not be bypassed completely. The VRO pump was bypassed as the oil function is no longer operative and I add the oil directly to the gas which seems to be the smart thing to do with an older motor.

 

[throwback2332]

Re: 1985 Johnson 150 VRO

A lot of people disable them for there own reason, well anyway the vro still has to be connected to the crankcase to pump fuel/oil mixture. Mainly you take a piece of hose put a screw in one end and a clamp on it then put the hose on the oil input side of the vro and clamp it down. You don't want air or water sucked in. Then you unplug the wiring harness to the VRO, leave the fuel lines hooked up.

 

[StratosRob]

Re: 1985 Johnson 150 VRO

Make sure your pulse line is in good working order.(not blocked or kinked)The pulse line is the only line running from the VRO to the engine block. If it is ok I would replace the VRO with ajust a new fuel pump not a VRO sense you are not using the VRO anyway. Its easy You just have 3 hoses one going to the carbs one going to the engine block and one coming from your fuel tank. The kits for the VRO are kinda hard to find and the new VRO is $$$$.
Hope this helps

 

[stingray6724]

Re: 1985 Johnson 150 VRO

What purpose does leaving the VRO connected at all serve if the oil moxing function is already disconnected? The repair manual shows a fuel pump near the VRO. If it's only purpose is to mix fuel/oil and send it to the motor, and it was already disconnected, can I just seal up all the hoses, with the exception of the fuel line and run the fuel directly to the motor?

 

[Big Keepers]

Re: 1985 Johnson 150 VRO

You said you have to pump the fuel bulb to keep the engine running. Does the bulb lose pressure and that is why you have to squeeze it? Or is it tight to the squeeze and you push fuel into the pump and motor? If you are losing pressure in the fuel bulb you have an air leak somewhere. The proper way to figure out where is to get a vacuum gauge and pressure gauge and T them into the fuel system. Using a clear plastic hose to see if air bubbles are present in the fuel when the motor is running. Ideally the vacuum gauge should read low numbers and the pressure gauge high numbers. There are specs to follow that can be found in service manuals.

First I'd start by inspecting the anti-syphon valve on the tank if you have one, you should. It should look clean, not rusty and the check valve inside won't require a lot of vacuum to open it up. If you don't have a valve there then inspect the fuel line leading to the fuel bulb and the line from the bulb to the pump/vro. Just because the bulb is 2 years old doesn't mean the check valves inside didn't fail. Thank ethanol for that if they did. A simple check is to remove the bulb and blow air through the end with your mouth in the direction of the fuel flow (the neat arrow on the bulb shows you this.) You should be able to blow air through. Now flip it around and blow. You should not be able to blow air through. If you can the check valves are shot, replace them.

Don't bother trying to rebuild the fuel pumps (separate from the VRO) its not worth it. They are cheap enough to replace completely. You will have a fuel lift pump that brings fuel to the VRO. It also receives pulses from the crankcase.

As an aside to your problem, the VRO's are still reliable if you know how they are supposed to work. A lot of the problems with the VRO's initally were the wrong type of oil being used. It wasn't thin enough to operate in the VRO and therefore, incorrect mixtures resulted. The VRO doesn't just mix the oil and gas, it pumps the gas to the carbs to be emulsified and sent to the intake.

The VRO is an air motor, fuel pump and oil pump comibined. Since 2 strokes don't need a 50:1 mix at idle the VRO was invented to lean out the oil/gas mix at idle and increase it gradually so that at full throttle you get 50:1. The air motor uses crankcase pulses to push a piston in the oil pump back and forth. The piston has a small slot that allows oil to enter the fuel pump portion of the VRO. Hence at low RPM the piston only moves slightly and allows small amounts of oil to mix. At full throttle the piston has full travel and you get the 50:1 mix. I'm going to school to become certified as a marine mechanic in general and will then begin working towards being Mercury certified. The teachers at my school all recommend re-connecting the VRO pumps and will not do the bypass for customers who request it. There is no reason to at this point since OMC and Mercury have basically solved the problems inherent with them. All newer motors (2 stroke) even EFI's have an automatic oiling system.

Yes they had their problems and a lot of mechanics would do the bypass procedure for you since they didn't want to learn how to make them work. They also are not worth rebuilding and its better off to replace the entire pump which is expensive unfortunately. It is possible that the VRO is the source of your air leak. As I said before the best way to find out is to T in a clear plastic fuel hose at different points of the system to see where the air bubbles are getting into the fuel system. My guess would be somewhere between the tank and fuel pump.

 

[stingray6724]

Re: 1985 Johnson 150 VRO

To Big Keepers: Thanks a million for the detailed reply. Strangely enough, my thought initially was that the bulb was bad, even though it was only 2 years old. Unfortunately, I listened to someone who said that was virtually impossible. The bulb is never hard to squeeze. I am guessing that might be the problem, but will follow your advise and check it out. If that is the problem, then I all I have to do is figure how to connect the VRO back up correctly.......hmmmmmmmm.

 

[Big Keepers]

Re: 1985 Johnson 150 VRO

I started digging through some of the material my teachers have been supplying me with. I also bought two books for these classes I take that have been very helpful. The VRO first started being used in Evinrudes around 1983 I believe maybe 1984. So you're boat will have one of the first generations of VRO pumps (they had nine different versions over the years.) Do some research before you try to tackle the VRO situation. I'll try to dig up some more dirt on it and I'll fire you off a PM here. I think I remember these being a bit cranky and prone to some problems but primarily it was because of the oil situation I spoke of. One of my teachers recommended to some of his customers that they add a small amount of two stroke to the gas in the tank as a precaution when fooling around with the VRO. Remember at idle you only need at least a 100:1 ratio. If you mix the gas in the tank at like 75:1 and test the motor at idle, you shouldn't have any issues. With seizing pistons or overheating. I wouldn't necessarily run it for an hour like that but then again theoretically it should be ok.

Understanding the Outboard Motor by Eugene Stagner
Boating Magazine's Outboard Engines: Maintenance, Troubleshooting and Repair by Edwin Sherman

I sleep with these books under my pillow. The first one is very indepth and gets technical. The second one is more of a DIY type of book that covers all 2 stroke and some 4 stroke motors from ignition through steering and tune ups.

 

[Joe Reeves]

Re: 1985 Johnson 150 VRO

Stingray...... Your problem does not invole rocket science mentality, no reflections internded..... just that it's an easy cure.

In pumping the fuel primer bulb, you are acting as a manual fuel pump, and when doing so, as I understand your first post..... the engine continues to run. Unless you have a obvious fuel/air leak which would cause the VRO to draw air, the following holds true.

This indicates that the VRO which is actually a straight fuel pump since you premix your gasoline and oil...... is faulty.

The cure is to either replace the VRO or rebuild it if a rebuild kit is available. The alternative is to discard the VRO completely and install the dual small fuel pumps..... yes it requires two (2). I don't have the fuel pump part numbers but I'm sure someone else here does.

 

[Big Keepers]

Re: 1985 Johnson 150 VRO

Exactly, the way a mechanic would try to find the leak would be to T in a vacuum gauge before the VRO and pressure gauge after the VRO and see what happens. Using a clear hose between VRO and carburetor would allow you to see air bubbles in the gas. If you have high vacuum and low pressure it may indicate an air leak. If you decide to replace the VRO with the two low pressure fuel pumps, they are diaphragm style and need two lines from the crank to supply pulses. You also need a place to bolt them to. I'm guessing there will be a spot that was intended for them and is free.

 

[stingray6724]

Re: 1985 Johnson 150 VRO

Exactly, the way a mechanic would try to find the leak would be to T in a vacuum gauge before the VRO and pressure gauge after the VRO and see what happens. Using a clear hose between VRO and carburetor would allow you to see air bubbles in the gas. If you have high vacuum and low pressure it may indicate an air leak. If you decide to replace the VRO with the two low pressure fuel pumps, they are diaphragm style and need two lines from the crank to supply pulses. You also need a place to bolt them to. I'm guessing there will be a spot that was intended for them and is free.

I sure appreciate the assistance. The VRO has been disconnected for years as best as I can tell. The boat ran fine the last couple of years since I bought it, just not now. If I go the dual fuel pump route, does anyone have a clue as to a part number for them?

 

[Big Keepers]

Re: 1985 Johnson 150 VRO

I go to Crowley's marine website and look at the parts lists they have for my motor. I'm sure you can find it there.