VRO Troubleshooting 1987 90-HP Johnson - Moderated Discussion Areas VRO Troubleshooting 1987 90-HP Johnson Author Topic: VRO Troubleshooting 1987 90-HP Johnson mburnette posted 04:42 PM ET (US) Just purchased a 1987 Montauk with a 1987 Johnson 90-HP that has been sitting for 'a while.' I was instructed to add Ring Free additive and run at full throttle which I did; and the Johnson 90-HP ran great for a couple of hours.
Compression is all above 120-PSI, and the motor will definitely reach top speed. However, after a while it started losing power, then regaining it, over and over.
Manual Motor Johnson Vro 90 Fuel
It also has much trouble idling without cutting off. This all leads us to believe it is a fuel pressure problem and more probable that it is the VRO pump on the fuel side. The 1987 Johnson 90-HP has all new fuel lines and tanks.
It has also had two new carburetor kits installed and a brand new fuel filter and water separator. Any other suggestions? Thanks in advance for your help. Dan posted 07:53 PM ET (US) I recommend a new VRO pump. The new ones are Ethanol resistant and I think the diaphragms are better too. If this solves the problem you're golden. As for decarbing the engine.
I think this is recommended every 30 hours. I do this with Johnson's Engine Tune decarb run through the Schraeder valve on your engine. I do this treatment two times. Do you also get the low fuel warning? A2J15Sport posted 10:37 PM ET (US) You may also be cutting out electrically, especially coils. The easiest way to check is with an inductive timing light.
Place the inductive lead on each plug wire as the condition presents itself. Contender posted 12:15 AM ET (US) I recommend you take off the VRO and mix your oil, remove the oil tank and lines, cap off the oil line on the engine, and now have one less problem. Good luck jimh posted 04:00 PM ET (US) When the engine seems to lose power, try squeezing the primer bulb to give it some more fuel.
This is a technique for diagnosing a fuel delivery problem. Loss of ignition in a cylinder will also cause a loss in power. Check the spark plugs to see how they look. A plug that is not firing should look different than the others. Twenty year old Power Packs have been known to need replacement, too. 15ftlover posted 12:48 AM ET (US) I had the same year and HP motor on a 25ft pontoon. The problem I had was very similar-losing power intermittently at speed.
Finally figured out it was a bad power pack (electrical) New one changed out for about $350. Hen TomB posted 11:34 PM ET (US) I agree with contender. Remove the VRO. I removed mine from my 1990 Evinrude on my 1979 Montauk 3 years ago, and am glad I did. It was over oiling and causing problems.
Now I know my mixture is correct and have had no problems. Also, manually mixing when you fuel up is no problem at all. TomB posted 11:36 PM ET (US) Sorry.forgot to mention you have to change fuel pump. Minor expense.
Tohsgib posted 12:23 PM ET (US) You do not need to replace fuel pump to disconnect the VRO. If pump is bad however then buy a new one that is NON VRO. I would do another compression test if you really ran her for a couple hours at WOT and a carb was lean due to sitting, she might be damaged. Mburnette posted 07:34 AM ET (US) Gentlemen, thanks for the input. The loss of power turns out to have been the VRO pump. Apparently the old Pate tank (which I removed and replaced witht he twin 12gallon tempos when purchased) was the gift that has kept on giving.
Some of the 'gunk' from the Pate tank's insides were clogging the fuel lines and pump. I took the boat out yesterday and it ran pretty good.no more of the loss of power. However, it still starts up like a two-stroke.have to idle at 3k rpm for a bit, but then idles fine once warmed up. Once warm, below 2k rpm, not idling, it sounds like it misses every once and a while.almost like I'm churning some mud or sand for a second then stops.
I know I'm not running aground because it will happen when I'm in the channel as well. It doesn't cut off the motor like before, but it doesn't sound right and certainly doesn't exude confidence on its passengers. Does this sound like electrical? The fuel tanks and pump are new and there are two new carb kits on it as well.
Hey everyone. New member and first time boat owner here. I just picked my 1991 Pro-Line 17' Center Console / Evinrude 90 HP VRO boat!!! It was a friend's brothers and I got it for virtually nothing. It has cleaned up nice even though the finish is oxidized since it has been sitting outside uncovered for 4 years. His brother was the original owner.
It has only been used about 60 hours. It has not been started in 4 years also. I am planning to get the motor running this weekend. I am sure that the fuel in the tank is bad and contaminated so I plan to use an alternate tank and gravity feed the motor. I called Evinrude today and was told that I do not have to unhook the VRO system and to just mix the fuel I plan to gravity feed 50-1.
And that I should be fine for a couple hours of running time That seems a little lean to me. I do plan to disable the VRO system latter. Will this procedure that I was told from Evinrude present any problems? I just want to make sure I do not do any damage Is there anything else I should do besides checking and cleaning everything electrical and replacing any internal fluids in the motor before I try to start it?
The motor turns over manually and seems to have very good compression. Thanks in advance!!!!! First step: Disconnect the VRO no questions asked. Second step: Make sure VRO is disconnected. Rebuild the carbs for sure. Change waterpump (Brand new waterpump, not just an impeller) Change lower unit oil.
You will not be gravity feeding anything. The fuel pumps pull the fuel into the engine Go to your local marine supply, buy a can of corrosion x and douse the entire engine, pull the plugs and give a little shot of it in the cyl. 50:1 is the correct ratio for that engine, a little extra wont hurt especially on the first tankfull. Remember extra is ok, Not enough is suicide.Disconnect VRO. (they sell a kit to plug it off and it only takes a few min to do.). I recently picked up a 00 McKee 18 with a 1999 V4 carbed Johnson VRO 115 HP and had the same debate. A lot depends on how you use the engine if you do a lot of idle it will foul plugs @ 50/1 less of an issue if you run wide open.
You might find article below of interest. As mine has the system check to monitor both oil level and no oil to engine I elected to leave the system in place. My System check lights come on at start up and I confirm this each time I start boat. Johnson outboard manual 115. IF I get a no oil light I will shut engine down and I always carry 1 gallon of oil so I can mix 50/1 if I have a failure. Yours engine has a horn and it has a special sequence for no oil and a different for low oil.
I suggest you keep VRO but make sure you understand the warning system and check it each time out. Hey everyone. New member and first time boat owner here. I just picked my 1991 Pro-Line 17' Center Console / Evinrude 90 HP VRO boat!!! It was a friend's brothers and I got it for virtually nothing. It has cleaned up nice even though the finish is oxidized since it has been sitting outside uncovered for 4 years. His brother was the original owner.
It has only been used about 60 hours. It has not been started in 4 years also. I am planning to get the motor running this weekend. I am sure that the fuel in the tank is bad and contaminated so I plan to use an alternate tank and gravity feed the motor. I called Evinrude today and was told that I do not have to unhook the VRO system and to just mix the fuel I plan to gravity feed 50-1. And that I should be fine for a couple hours of running time That seems a little lean to me. I do plan to disable the VRO system latter.
Will this procedure that I was told from Evinrude present any problems? I just want to make sure I do not do any damage Is there anything else I should do besides checking and cleaning everything electrical and replacing any internal fluids in the motor before I try to start it? The motor turns over manually and seems to have very good compression. Thanks in advance!!!!!I kept the OMS system, they stopped the VRO yrs ago.
If bypassed you lose some features such as the alarm system. I would do a complete servicing before starting it, do everything, heres what I did. Rebuild carbs with new kits, compresion test so you know what the condition is, spark test it. Change the lower gear oil, use NEW seals on drain plugs or expect water in the gears. Remove prop, clean shaft, check for fishing line, relube and install prop. Change fuel filter on the engine, add tilt fluid.
Lube the steering tube and tilt tube, all pivot points. DRain oil tank, refill, purge line of air before connecting to engine, add oil to fuel tank until you are certain the oil level is drawing down in the oil reservoir. Remove, clean, reinstall with dialectric grease all major connections starting from battery, if it uses wing nuts THROW them as far as you can and buy proper nuts with spring washers, all stainless. Install new sparkplugs, use the correct champion plugs, not NGK bandaid plugs.
Get the factory service book, read it through, don't rely on internet opinions, then try starting it on the water hose, expect rpm to be high, 1000rpm is normal. I did all that and mine runs like a clock. Back in the mid-90s, I had a 1990 90hp with VRO. Never had a problem with the VRO during the several years I owned the boat. There is nothing wrong with pre-mix in the tank while the VRO is still active. Actually, that is what your supposed to do after you overhaul or maintain the VRO system, until you verify the VRO is working properly. It will actually result in a slightly leaner fuel as there will be less gas in the fuel / oil mixture that is going into the intake.
But you should be fine. 50:1 is the correct ratio. If your planning on keeping your VRO, here's what I would do. Clean out, and repace the filter in the oil resivoir.
Replace the oil line from the resivoir to the motor. It might be the old vinyl line and they crack. Check all of the 'C' shaped ratchet clamps under the cowling. Mine started to break on their own. They just get old and brittle.
After you've done what I mentioned, you have to bleed the air out of the oil line. Get use the primer bulb on the oil line to get the oil all the way to the end of the oil line before you install it. Use pre-mix until you verify the VRO is working. There's a sight glass you can view the oil passing up into the VRO. If the sight glass is the color of the oil, the VRO is drawing oil from the tank. If the sight glass is clear, there's something wrong and it's not drawing oil.
There was a really good article about VRO awhile back in Trailer Boats magazine. I have a hard copy of it. Supposedly, the really bad years for VRO were the first year or two after it came out. I think it came out in '86.
I also have a 60hp that I disconnected the VRO. Not because I didn't trust it, just because I have 2 motors on the boat, one was pre-mix and the other injected. I didn't like having to have two seperate fuel tanks so I disconnected the VRO from the 60hp.
I bought a 120 Johnson new in 1991- bigger block V4. It gets plenty of use and still has the original VRO. I have logged every gallon of fuel and oil consumed over the lifetime of the motor. The long-term average is almost exactly 50:1.
Pre-mix 50:1 fuel/oil mix is what the OMC manual instructs owners to use after breaking open the oil plumbing on the VRO. The pre-mix ensures the motor has sufficient oil in case the VRO is not pumping oil. That mix should be used until you are certain the VRO is pumping oil (level in the tank drops).
Some people fear the VRO, saying it pumps too much or too little oil. My experience- too much oil means one of two things have happened: - The owner has switched to a lower viscosity (i.e., synthetic) 2-stroke oil that the VRO pumps faster. The VRO was designed in a world where OMC only sold 1 grade of 2-stroke oil. Run XD-30 in a VRO system. The fuel line has cracks or leaks on the suction side of the pump, admitting air in the fuel stream and upsetting the fuel-oil ratio. If the VRO is pumping too little oil, check the oil lines for the same cracks and leaks for the same basic reason. Pull the VRO oil reservoir and clean or replace the filter on the pickup end of the oil line.
There is a pulse dampener screwed into the block with a hose fitting to provide pressure pulses to drive the VRO. The original pulse dampeners were black. An improved dampener is available, colored blue. Replace the black pulse dampener with the blue one. My dealer kept both black and blue pulse dampeners under the same part #. Your '91 VRO is probably a VRO-2, which has ethanol-compatible components. My experience- too much oil means one of two things have happened: - The owner has switched to a lower viscosity (i.e., synthetic) 2-stroke oil that the VRO pumps faster.
The VRO was designed in a world where OMC only sold 1 grade of 2-stroke oil. Run XD-30 in a VRO system.The oil pump is a positive-displacement (piston) pump, so lower viscosity oil would not pump faster. If anything it would pump less (more leakage around the piston) but for the low pressures involved it would be insignificant.