Bad VRO pump or ???

[jmahler]

I own an 87 200 hp carbed Merc. Well, I was boating today, cruising at 4000 when the motor dropped in RPM's and the beep was a constant fast beep from the controls. I shut it off and was able to determine it wasn't the cooling system, so it was the VRO. I started it up and it beeped again. I took the VRO tank out and poored the oil into the tank, took the fuel line off and primed the bulb until it looked mixed. I drove back at 1200 rpm with the beeping. The motor was not able to go much higher. I got it home and did a compression test and had 120-125 across the board! That is the good news. I need to know what to do next. What do I check and I know a lot of you guys love to bypass this system, but I like not having to deal with the mix. I need some input of where to go to diagnose this. Thanks in advance..... I know you guys up in the midwest must hate me for boating this late in the season, but with 80 degree temps, how can you not....

[jmahler]

I own an 87 200 hp carbed Merc. Well, I was boating today, cruising at 4000 when the motor dropped in RPM's and the beep was a constant fast beep from the controls. I shut it off and was able to determine it wasn't the cooling system, so it was the VRO. I started it up and it beeped again. I took the VRO tank out and poored the oil into the tank, took the fuel line off and primed the bulb until it looked mixed. I drove back at 1200 rpm with the beeping. The motor was not able to go much higher. I got it home and did a compression test and had 120-125 across the board! That is the good news. I need to know what to do next. What do I check and I know a lot of you guys love to bypass this system, but I like not having to deal with the mix. I need some input of where to go to diagnose this. Thanks in advance..... I know you guys up in the midwest must hate me for boating this late in the season, but with 80 degree temps, how can you not....

[Chris E]

is the oil tank on the engine empty or full (not the big tank). If it is not full, the alarm will go off.

[jmahler]

The reserve tank on the engine is filled to the top.. What now?

[Chris E]

get me your serial number please i want to check something

[jmahler]

The serial # is 08230203. I hope this helps and thanks...

[Blizz]

Just disconnect everything and run premix unless you really prefer oil injection. Most performance guys will tell you it's the first thing they do just for piece of mind they always seem to fail at the wrong time.

[jmahler]

Say I do disconnect it, then how to do I go about doing this? I know there is a right and wrong way to do it. I would like to get at least another season out of her before I upgrade to a newer 250. Will the alarm still work if the motor gets hot or will all of that go out of the window?

[JW]

Get the kit from RickRacer. You must install the special part that takes the place of the pump. The kits are complete and easy to install.

[jmahler]

Well, after reading all the horror stories over at scream and fly, I have ordered the kit from Rickracer. Got the S&F discount. Thanks JW for the advice and Piro over at S&F had a lot of info for the install. I hope it all works out when I install it. Thanks again.

[Blizz]

You'll be happy that you did and have piece of mind also..

[jgreen]

jmahler,

Go back to page 4 in this forum and check ot the oil alarm topic there is a link posted in there that tells you how to trouble shoot it.

[jmahler]

Thanks Jgreen. Chris E was nice enough to send me the info on where to check for problems. Did you get the kit and remove it from yours? I have been reading up on it and it sounds like you have to remove a lot of crap. I ordered the kit and when it comes in, I will tackle the job. I see that you just disconnected the wire to the alarm. Did that allow the engine to run normal again? When the engine dropped in RPM's a second later the alarm was beeping away. I had to sputter home (after I mixed the oil in with the gas).

[jgreen]

Mine never dropped rpm's, it never ran poorly it always ran fine jusc the annoying beep, I have the kit but havent put it in yet, we are still thinking the problem is in the ECM I checked to see if it was pumping when the alarm was on (after I had pre-mixed my gas)and it was, but the alarm stayed on so I disconnected the wire for the oil alarm and have been running pre-mix just in case.
Next spring I am going to plug it back in, and when it goes off I will try a different ecm that a local dealer will let me try to see if it solves it.

[jmahler]

Have you red all the horror stories about these oil injection systems failing with age. Your engine is over 10 years old. Aren't you afraid it might break? That is kind of odd that your engine being an efi and all, didn't cut the rpms. I was really scared to do a compression check when I got home, but it was all good! I really don't need to put another engine on it since I just paid the boat off this summer. I want to enjoy it without having to dump 8 grand for a newer one. We all know what B.O.A.T. stands for......

[bdusted440]

You're rpm's more than likly was due to too much oil in the fuel.The oil level sensors go out after tyme. unplug the sensor and see if it stops.never had a vro fail on a stock motor. Keep in mind the guy's on screem & fly are hot rodders with modified engines.Cranking high rpm's

[Inline Six]

The oil pumps on the merc motors are good. They don't fail unless you run them past their limits. If you keep a stock motor under the rev limiter it will be fine. The guys on scream and fly will probably negelct to tell you that they unhooked their rev limiters (as most of them do) because everyone figures that turning faster is the key to higher speeds.

Like anyone when something fails its hard to admit that you had something to do with it. I have run stock V6 mercs with oil injection for years and they never fail. Keep them under 6200 rpm and you're fine. Its when people start turning over 7,000 that you get failures. The little plastic gear in the oil pump just can't handle those rpm's. Also, those motors wear out a lot faster when you swing them that fast.

If you want to turn 7+ get a 2.5L high performance motor. They have completely different powerheads to withstand that kind of abuse. They don't last too long either compared to a stock motor uncer its rev limiter but you get more speed for you displacement.

I like premix better but it costs money to change them over and you use more oil with a premix. If you are worried about your injection system disassemble it and see if all the parts are within spec. If they have wear, then consider switching to premix or fixing the parts. If you don't feel comfortable doing this take it to a marina. In the grand scheme of things what would be better saving a few hundred dollars trying to fix a problem yourself or $10,000 plus on a new motor because you messed up your injection system?

VRO pumps are the pumps used on the OMC motors. They are a different breed from the merc stuff. They fail without warning, especially on the smaller 3 cylinder looper stuff. I always rip those off and replace with a mechanical fuel pump. They are pretty much a modern version of the old merc AutoBlend systems which I wouldn't wish upon my worst enemy...

[jgreen]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Aren't you afraid it might break? </div></BLOCKQUOTE>


I was, but like bdusted and other people have told me, the ones that fail are usually the ones that run really high rpm and mine being an efi cant turn that fast and even if the gear does break it is plastic so it wont take the motor out the alarm would come on before the damage was done, then you just pre-mix like you and I have already done. I like the convenience of the oil injection and if we can get the alarm to stay off, I will keep it.

[jmahler]

Thanks guys. I didn't think about the rpm's and how those guys spine those rpms high. I am glad that you told me that. I will look into what is the problem and fix it. Bdusted, the engine dropped RPM first then the alarm sounded. I then mixed the oil in the gas and sputtered home. I am not sure why the rpm dropped like that. I will check the cylinders for spark and go from there but I know the compression is good. Any other ideas as to why the rpms dropped like that?

[Inline Six]

It could be a lot of things. Maybe you blew a power pack? A reed? Its hard to diagnose without hearing the motor. If the oil borke you would seize it more likely than blowing a piston anyways...

[jkeiper]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Keep in mind the guy's on screem & fly are hot rodders with modified engines.Cranking high rpm's
</div></BLOCKQUOTE>

EXACTLY!

If your alarm is going off you need to figure out what is causing it. (unless you are determined to go to premix) That is what it is there for. The Merc. system is just fine if you don't change the RPM limiter. Premixing isn't much fun if your like me and go through 30-50 gals of fuel in a weekend.

The Plastic gear on the crank isn't that hard to change if it fails as long as you don't runit so long it seizes the motor.

Jim
Jim

[jgreen]

jmahler,

jkeiper told me also to look at the charging system, sometimes low voltage can apparently trigger that alarm also.

[jmahler]

Thanks guys. I am working this week and weekend (traveling) but I will try to fix it next weekend. I will keep you up to date...

[Scream And Fly]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Inline_Six:
The oil pumps on the merc motors are good. They don't fail unless you run them past their limits. If you keep a stock motor under the rev limiter it will be fine. The guys on scream and fly will probably negelct to tell you that they unhooked their rev limiters (as most of them do) because everyone figures that turning faster is the key to higher speeds.

Like anyone when something fails its hard to admit that you had something to do with it. I have run stock V6 mercs with oil injection for years and they never fail. Keep them under 6200 rpm and you're fine. Its when people start turning over 7,000 that you get failures. The little plastic gear in the oil pump just can't handle those rpm's. Also, those motors wear out a lot faster when you swing them that fast.
</div></BLOCKQUOTE>

I'm not even sure where to begin here, so I'll keep it short.

Yes, the pumps fail at ANY RPM from a variety of factors - even age.

The plastic drive gear becomes weak with age and general use - I would not hesitate to remove that oil injection system. You're rolling the dice by running a system that old.

We don't just figure that high RPM is required for making good power up top, we know it. http://www.checkmate-boats.com/infopop/emoticons/icon_smile.gif

[Inline Six]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Scream And Fly:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Inline_Six:
The oil pumps on the merc motors are good. They don't fail unless you run them past their limits. If you keep a stock motor under the rev limiter it will be fine. The guys on scream and fly will probably negelct to tell you that they unhooked their rev limiters (as most of them do) because everyone figures that turning faster is the key to higher speeds.

Like anyone when something fails its hard to admit that you had something to do with it. I have run stock V6 mercs with oil injection for years and they never fail. Keep them under 6200 rpm and you're fine. Its when people start turning over 7,000 that you get failures. The little plastic gear in the oil pump just can't handle those rpm's. Also, those motors wear out a lot faster when you swing them that fast.
</div></BLOCKQUOTE>

I'm not even sure where to begin here, so I'll keep it short.

Yes, the pumps fail at ANY RPM from a variety of factors - even age.

The plastic drive gear becomes weak with age and general use - I would not hesitate to remove that oil injection system. You're rolling the dice by running a system that old.

We don't just figure that high RPM is required for making good power up top, we know it. http://www.checkmate-boats.com/infopop/emoticons/icon_smile.gif </div></BLOCKQUOTE>


You could say anything on the motor will fail from age. Thats a risk you take with anything on a motor. The fact is if the system wasn't designed to work it wouldn't be on the motor. If you maintain anything right it will last.

As with the RPM comment, I believe the factor to consider here is that these are STOCK motors. That means they aren't designed to be run that fast. You don't need to turn super high RPM's to go fast. You will gain a little more on the top of a stock motor if you spin it that fast but not enough to make it worth while. The porting is stock so you won't develop the power you could on a high performance motor. The motor in general is not designed to do that kind of work.

The bottom line is if you run the motor under the rev limiter you are going to have a good running motor that lasts a very long time. If you want to spin 7,000 plus BUY A HIGH PERFORMANCE MOTOR. They are designed to run that high. By trying to turn a stock motor into a high performance motor you are going to waste a lot of time and money and still fall short of what a good 2.5 260 or 280 will do.

I have a 200 merc with oil injection that has been run for years without any problems. The motor still runs great and still develops its hp. The leakdown is WELL under 10% on each cylinder. The oil injection system has been maintained and has had parts changed. I use LESS oil than if I were running pre mix and that results in money in my pocket. The price of maintaining the injection system is well lower than the cost of the oil I would have used as a pre mix motor.

[Inline Six]

The only time I have seen a properly maintained oil injection system fail is on a Pro Max that was swinging WAY past the rev limiter. The little plastic gear failed due to stress. If the motor was kept under the rev limiter I am sure it would still be here today.

[Scream And Fly]

I see what you're saying, but I'll just have to agree to disagree with many of your points. http://www.checkmate-boats.com/infopop/emoticons/icon_smile.gif

After all, we don't have a lot of experience in this area. http://www.checkmate-boats.com/infopop/emoticons/icon_wink.gif

Greg

[Chris]

Fellas.

I have a '91 XR4. I asked my tech this year about the gear drive and I mentioned to him I had heard about them failing. So I asked about replacing the gear with a new one. He told me he's hardly ever seem the one on my particular model fail. He said the OMC system fails a lot but the Merc one he said is usually pretty reliable. And he's a 'JohnnyRude dealer.

Where is the gear that fails?

[Scream And Fly]

Chris, the OMC VRO system uses engine vacuum pulses to drive it, whereas the Mercury system uses a mechanical Mikuni pump driven by the crankshaft.

The Mercury system is more reliable, but the pump itself is driven by a plastic coupling off the crankshaft. I have seem many fail in stock engines. I'll just leave it at that.

Greg

[Chris E]

Just as an aside, i got this advice many years ago from a respected marine mechanic in the area, he told me: "NEVER run an engine at more than 3/4's throttle, as long as you do that it'll run forever". My dad's 68 larson is on it's 3rd owner now and has only ever seen regular maintenance and a valve job (at 20 years)in it's almost 40 year life. Even though this thread pertains to outboards, the advice holds true, if you beat it, it won't last and it doesn't matter whose name is on the hood.

[Inline Six]

So you're telling me that you know more than the engineers who designed these systems?


Yes I see them fail too...when you go over the rev limiter

Bottom line: If you want to over rev, get a high performance motor.

If these oil injection systems are so bad then why have none of mine ever failed? I've run several V6's from the late 80's and 90's and have NEVER had problems with the injection systems.

I ran the exact same model V6 merc 150's with oil injection and without oil injection. Same mods on the same motor. Ran both at 6,200 and the only difference was the premix used more oil and didn't run as nice as the injection system as the thing was running 50:1 all the time as opposed to the lower ratio the injection system runs at idle.

Why was it when I asked two of the top high performance mechanics in Ontario about disconnecting them they told me not to bother? Why do they both have the oil injection connected on their mercs on their family boats?

Its because they are a sound system. The only time the break is when they wear out from extreme use.

I think you would be hard pressed to find one system on a V6 merc (besides autoblend) that has failed where the motor has not been run excessively hard or has not been over revved.

If you want ot over rev your engine thats your business but the oil injection doesn't fail due to a flaw in design...it fails due to a flaw in the operator.

[Scream And Fly]

No, I'm not telling you we know more than the engineers that designed the oiling system. Is that what you're telling me I said?

Out of respect for Chris, I'm not going to debate this subject. You win.

I'll talk to Helmut about our 'operator flaws'.

Greg

[Chris]

How hard is it to replace the small gear?

Personally, I like the injection because it smokes less. A lot less if it fails too! http://www.checkmate-boats.com/infopop/emoticons/icon_biggrin.gif

Just kidding...

A few years back I bought a '87 merc 60 and it was newly rebuilt. I asked the marina what went wrong and they told me the oil injection failed and it burned a piston. They rebuilt the powerhead and sold the motor with the injection system bypassed.

So they do fail from time to time.

[JW]

If you buy used outboard, ALWAYS remove the oil injection system. Why?

You really have no idea how the previous owner(s) used and abused a motor. I always remove the oil injection system when I get a used motor. The gears are plastic and will eventually fail. Just because Inline six has never had an oil injection pump fail, doesnt mean the millions of motors out there have all been reliable. Yes, stock motors turned less than 6,000 rpms have had oil injection failure, and yes it will cause engine damage BEFORE you hear the horn and get the motor shut down. So basically it boils down to: Do you trust yourself to mix the oil, or do you trust a plastic gear set to hold together on your Merc?

I use the oil injection on my new motors because of warranty, and then for maybe 5 years after that. I don't keep a new engine long enough to need to replace the pumps or remove them. I just remove them on used motors that I buy to run on my used boats................