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Author Topic:   Mercury 225-EFI Fuel Consumption

assaf posted 12-30-2005 12:16 PM ET (US)
I own a 1998 Outrage 21 with a Mercury 225 EFI. The motor is working flawlessly. Recently I installed a NAVMAN 2100 fuel flow meter and found some interesting facts. At idle speed in neutral gear fuel flow was not less then 2.3 GPH. At a slow trolling speed 4-MPH fuel flow was 2.9 GPH. At 6-MPH fuel flow was 4 GPH. Compare that to test data that reports an OptiMax of equivalent HP and boat that at 5-MPH the fuel flow is 0.8 GPH. [My motor shows about] four times the consumption! Is some thing wrong? At 3,600-RPM the boat speed is 29-MPH and fuel flow is 13-GPH. That is 2.23 MPG .
rtk posted 12-30-2005 01:21 PM ET (US)
I have a 1997 21 Outrage with a Mercury 250 EFI. I don't pay much attention to low speed fuel mileage, I do beleive at idle fuel burn is around 3 gallons per hour.
At 3,600 RPM my results are almost identical to yours. My best economy figure at 30-MPH, around 3,600 RPM was around 11 GPH, or 2.7 MPG
At a 25-MPH to 30-MPH cruise, fuel flow is typically 10-12 gallons per hour, or 2.5 MPG. When the wind or seas kick up a bit the fuel economy drops.
Fuel flow is measured by the Smartcraft system.
Did you ever check out the rate of fuel flow at wide open throttle? It is not for the weak of heart or pocket book. Mine is 29 gallons per hour, 48-MPH.
The Optimax and EFI fuel delivery systems are very different.
Rich
jimh posted 12-30-2005 08:41 PM ET (US)
I don't see any basis whereby it is reasonable to assume that a conventional port injected two-stroke engine and a direct-injected two-stroke ought to have similar fuel economy. Therefore, it is not at all surprising that the fuel flow figures reported for an OptiMax do not match the fuel flow figures you see for your EFI model.
fourdfish posted 12-30-2005 09:14 PM ET (US)
According to results I've seen the Optimax has a very low fuel consumption at idle. (.5gph or less) Of course it idles at a lower rpm than the EFI, which might might account for some of the difference. I think the higher rpm fuel consumption is better also!
assaf posted 12-31-2005 04:00 AM ET (US)
I didnt want to say that the optimax and the EFI ought to have similar fuel economy, I know they don't. but the fact that at trolling speeds and lower rpm the consumption is 3-4 times higher was very surprising to me.
dauntlass 18 posted 12-31-2005 08:27 AM ET (US)
My model year 2000 200 hp Optimax on a 21ft Conquest burns about 7 to 8 gallons per hour when run in the 2800 to 3000rpm range.I base this on running the boat about 3 hours and than filling up the tank.It takes 22to 25 gallons to fill the tank.When I run the boat in the 3500 to 3800 rpm range for the same 3 hours it takes about 30 gallons to fill the tank.
jimh posted 12-31-2005 09:55 AM ET (US)
Idle speed operation is the region where the classic two-stroke motor is the least efficient. On my older two-stroke, the fuel economy (miles-per-gallon) tends to improve with engine speed. Idling along gives me worse fuel mileage than cruising at 30-MPH.
The newer direct-injection motors get five or six times better fuel economy at idle speeds than port-injection motors. The direct-injection motors typically are operating in a stratified charge mode and are running very lean mixtures, perhaps on the order of a air:fuel ratio of 30:1 or higher.
assaf posted 12-31-2005 03:57 PM ET (US)
So I assume that in the real world , and not on the reported tests, the difference in the 3500 rpm zone between the DFI and the EFI, is about 25% less consumption for the DFI , am I wrong?
rtk posted 01-01-2006 11:07 AM ET (US)
While we are running around 2.5 mpg at cruise with our conventional two stroke efi engines, I have heard, or read reports that the Optimax cruise mpg is a bit over 3 mpg. Similar weight boats, lenghts and horsepower.
So your 25% figure is probably not out of line for comapring fuel costs when comparing the two motors.
I think 30% better efficiency at cruise has also been used when comparing the two technologies.
I thought real hard about spending the extra money for the Optimax. When fuel was $2.40 a gallon the payback estimate was over quite a few years. With fuel raeching $3.75 a gallon at one point this summer, I am questioning my decision of not buying the more efficient engine. The payback comes alot sooner with higher gas prices.
Over two seasons my has performed flawlessly also.
Rich
aquaman posted 01-02-2006 01:24 AM ET (US)
From test reports, talking to factory reps and experience, DFI and EFI outboards fuel consumption at cruising speeds and WOT are very close. The DFI engines may have a fuel saving of less then 10%. Even the large 4 strokes don't show much better fuel ecomony then the DFI/EFI at cruising speeds. Just my 2 cents...
assaf posted 01-02-2006 06:14 AM ET (US)
Rich , if you thought fuel is expensive , in our country we pay nowadays JUST 4.55$ a gallon. Asaf.
rtk posted 01-02-2006 03:16 PM ET (US)
Ouch assaf. I started twitching a little when the price went well above $3.00 a gallon.
Aquaman, I wish there was a database of Mercury reports to view. I also wish I could bolt on a 225 Optimax and see how it does. Same boat, same Smartcraft system. Your numbers could very well be reality- I honestly only have reports of individuals running the 225 Optimax, and I noticed very good fuel economy numbers for that motor.
I really have no complaints on the fuel usage of my engine. If I lay off the throttle she runs pretty efficient even with a load.
It is a very low maintenance engine also. Reading through the service manual there is not a good deal of maintenance to do. Very easy to service and do preventive maintenance.
Rich
BW23 posted 01-02-2006 07:39 PM ET (US)
I have a 97 225 EFI on a 23'Conquest running a 15P MIRAGE prop. Here are a few #'s using a Standard Hzn FF41 fuel flow meter.
RPM 3600 13.5 GPH
3800 14.2 GPH
4000 15.5 GPH
4600 19.3 GPH
5000 23.0 GPH
5400 28.3 GPH
LHG posted 01-05-2006 04:34 PM ET (US)
From what I understand, none of the 3.0 liter V-6's, any brand, get very good fuel economy. My guess is that an EFI system does offer an improvement over the carbs, as I think both the Merc EFI and Yamaha OX66 do better than the carbed OMC's.
A Whaler engineer told me they couldn't believe the HUGE improvement in fuel economy on a 320 Outrage when they repowered from twin 250 EFI's to twin 250XS Optimax's. He said these engines really improved the overall running qualities of the boat. And from the B&WB mag shootouts, we know the Optimax's are the fuel mileage champions of DFI's. And now the 250 Verados have even better running quality than these Optimax's
Mambo Minnow posted 01-05-2006 05:41 PM ET (US)
ASSAF,
I am purchasing a 98 CONQUEST 21 with 200 MERC OFFSHORE (non EFI version). Your motor is a close relative. Can I ask specifically where your oil reservoir tank (the big one) is mounted? I know it is near the battery compartment. I need to replace the oil injection system removed by original owner. Any photos you can post would be most appreciated!
dauntlass 18 posted 01-05-2006 07:51 PM ET (US)
The motor well on the 21 Conquest has a pocket molded into the well on the port side looking fordward.Every one I have seen has a flush mount fitting in the pocket similar to the fuel fill which is on the port side about admid ship.The fill fitting in the motor well has a hose attached to it and on the bottle end a screw on cap.You just unscrew the flush deck fitting and fill the bottle with a automatic trans. fill funnel .I guess 1.5 gal fills it.I am refering to the Mercury bottle which I beleive to be oem on the boat
fourdfish posted 01-05-2006 07:54 PM ET (US)
LHG-- We just went over the B&WB mag shootout on another thread about the fuel economy and yet you go back and say that the Optimax has the best DI fuel economy when you know that was not a legitimate conclusion or test for that matter.
Now, I hope you are not saying the 250hp Verados have good
fuel economy when absolutely no one is saying that. In fact everyone says they have the worst WOT fuel economy. And the new Verados also are showing the worst fuel economy, according to Powerboat Reports.
Just another of your Mercury commercials! I guess the fact that many are turning to Suzuki is getting to you.
gss036 posted 01-05-2006 08:33 PM ET (US)
MamboMinnow, before you get too deep into replacing the oil injection systems, find out why it was taken off. If the pump gears were bad, it will require a powerhead removal tear down to replace the drive gear. Really an expensive deal. Some people are going to the new electric oil systems. Just a thought.
Mambo Minnow posted 01-05-2006 10:08 PM ET (US)
I paid an independent mechanic to survey and run it...it appears original owner just did not trust system and completely removed the system and direct mixed 50 to 1. I do know to look for damage to the plastic gear wheel for oil injection and got quote of $1100 to fix that if it were bad since requires cracking the block. I have my doubts, but don't know how to inspect from the outside if gear wheel is inside the block. Any tips? Compression on all 6 cyls is good at 120 psi. Everything but the oil injection system checks out in spec. I have not heard of electric oil injection technology...any details? Sounds like might be a better retrofit option for me.
gss036 posted 01-06-2006 12:33 AM ET (US)
http://www.pamlicomarine.com/msi-eoi.shtml
Check out this site. They have the electric oil injection system. I have never seen one in use so I can't help out there.
I am sure there is a way to look at the plastic gear w/some type of bore light inspection tool but finding one might be something else.
Mambo Minnow posted 01-06-2006 07:39 AM ET (US)
That is the most useful info I have received regarding this engine! Obviously, this must be a pretty common problem with this engine series for them to make this unit. You probably did not notice, but the site has a paragraph on how to test for oil gear failure! Many thanks for the tip!
jimh posted 01-06-2006 09:00 AM ET (US)
Mercury engines use a plastic gear to drive the oil injection pump. Failure of this gear is possible. See:
http://www.outboardrepairs.com/topics/005290.html
http://groups.google.com/group/rec.boats/browse_thread/thread/ 91f515ab61b262e4/71eaf2a11220a236%2371eaf2a11220a236?sa=X&oi=groupsr& start=0&num=3
http://groups.google.com/group/rec.boats/browse_thread/thread/ 90ac6ccb73b946d5/8a73df149ccc434f%238a73df149ccc434f?sa=X&oi=groupsr& start=1&num=3
http://www.biggerhammer.net/mercury/
http://www.outboardrepairs.com/topics/001915.html
for some discussion of this problem.
Mambo Minnow posted 01-06-2006 10:03 AM ET (US)
JIMH and GSS...thanks for all the references. Think I will just continue to pre-mix 50 to1 like previous owner and put the $1000 into an interest bearing account for five years to save a down payment on a new ETEC or four stroke. Boat and trailer are in excellent shape. The motor appears to have been saved from catastrophic damage based on good compression and leak down tests. Motor definitely worth low end of the resale spectrum...my guess $3000 max.
LHG posted 01-06-2006 01:25 PM ET (US)
The Mercury 2-stroke oil injection system is basically bulletproof, and has been since day one. The plastic crankshaft drive gear is not a defective component just because it is plastic! If so, it would have been changed years ago, and not used on the latest blocks. Conversely, it is a successful component of the system.
From what I have seen, most of the Merc or Yamaha disconnected oil injection systems are because the previous engine owned by the person was an OMC, or because the engine was raced at very high RPM of 7500 or so. There is a lot of misinformation out there.
On the EFI's, you CAN't disconnect the oil injection system and it is controlled by the ECM. (at least that's what my mechanic told me). I have thousands of hours on 5 oil injected Mercury V-6's, and never the hint of any oiling problem. As the oil injection pump wears out, it actually over-oils the engine by it's design, and the oil automatically gravity feeds the engine from the engine mounted tank. When the alarm sensor module (which senses both the drive gear operation and oil level in the engine tank) is failing, is also sounds repeatedly, rather than going silent. It's a pretty good fail-safe system.
If a Mercury V-6 self destructs from no oil lubrication, it's most likely the idiot behind the controls or lack of competent routine maintenance (such as oil tubing replacement on some maintenance interval)
Tom W Clark posted 01-06-2006 02:03 PM ET (US)
Larry,
Your comments on the oil injection systems are substantially incorrect. All outboard manufacturers have had some failures of their oiling systems, Mercury is no exception.
The original "Auto Blend" oil injection from Mercury was a disaster. The newer "Advanced Oil Injection" system has been highly reliable but not "bullet proof". The design of the Advanced Oil Injection pump has changed at least three times as the design has been improved to make it more reliable.
I know all this after doing extensive research this summer troubleshooting my mechanical troubles on my Mercury 150 oil system.
The OMC VRO system has the great advantage over-oiling the fuel mixture when it fails whereas the Mercury oil system failure will lead to a no-oil condition and ruin the powered.
The myth of the OMC VRO unreliability has been introduced, maintained and repeated over and over mostly by you here on ContinuousWave. I wish you would give it a rest.
fourdfish posted 01-06-2006 03:08 PM ET (US)
Larry said "From what I have seen, most Merc or Yamaha disconnected oil injection systems are because the previous
engine owned by a person was an OMC"
When I read that, I couldn't stop laughing! That is by far one of the most ridiculous statments you have ever posted here!
And you have posted some real winners!
1st You are saying that all kinds of people have switched outboard brands and then took the oil injection system off thier Merc engines that they purchased! OMG, are you lost?
2nd The OMC VRO is very reliable and I had one on my last
engine for 14yrs without a single problem. So many others have had them also to make that completely false.
3rd You post without thinking about what you are writing.
Tom-- I think enough people here have read Larrys posts to
know whats up here! The word "substantially" is being kind!
LHG posted 01-06-2006 03:34 PM ET (US)
Tom - Wherever you are getting information on the Mercury "Auto Blend" system, it is incorrect. From the day Mercury's oil injection system was introduced (don't know the exact year), Mercury V-6's only used the integral, up to 100-to-1 oil injection system, and it has been excellent. I'm sticking by my post and my own experiences. The Auto Blend was an add-on, detached, blender box used for the 1986-1988 in-line 6's, and other smaller Hp versions of that block, and had nothing to do with the V-6's. These smaller engines were never designed for integral oil injection, and it was a stop-gap measure until Mercury caught up with OMC and Yamaha and got it's new L3 and L4 true oil injected engines out in 1989. I have no information or experience on the fixed 50-to-1 Auto Blender accessory, and don't know if it was good or bad. But I do know that when I powered my 1986 Outrage, I specifically looked for 1985 115's since they did not use this Auto Blend box, which I did not want to clutter up my transom splashwell rigging. The pre-mix 1985's made it a lot easier and cleaner.
Nor, obviously, do I have any experience with the OMC VRO systems. I only know what I have seen here repeatedly, and in other places. I do know that in the late 80's OMC replaced over 3500 blown powerheads, under warranty, with the blame supposedly laid to the VRO. Maybe this OMC VRO stuff is all urban legend, or was from owner error, I don't know, and the system was perfect. But searching around CW, you will see lots of threads, by others, of their VRO problems. They continuously mention that their VRO is disconnected for some reason unknown to me. I've had no reason to disconnect the oil system on my Mercs, nor have I ever been advised to do so, nor have I had to rig up any expensive, retrofit alarm system to the engines, either. If you are going to do it on your engines as a precaution against failure of Mercury's system, be my guest, but pre-mixing 50 to 1 into a 140 gallon tank sounds like a lot of uncecessary work and expense to me. It's bad enough on my 18 Outrage 63 gallon tank
Mambo Minnow posted 01-06-2006 04:47 PM ET (US)
I can say that practices vary region to region. I have discovered here in FL from several Merc Master certified techs, I have contacted, that this FL market unfortunately has alot of cases of misinformation leading to removal of Merc oil injection system. One tech from Northeast like me, who never saw this stupidity until he came south to FL.One dealer even convinced a naive owner to remove system, when still under warranty, he could have received a no cost repair!
My dad has an 84 Evinrude 90 V4 and has never had any problem with the VRO system at all in all those years.
Tend to agree pre-mixing 92 gallon tank is going to be a pain, but I think I will deal w/ it until I can repower down the road in five years.
FYI: The master tech had heard of the electronic system previously mentioned....apparently it was presented to Mercury for their consideration, but rejected. It seems the key to this motor avoiding failure is to not procrastinate on periodic 100 hr service maintenance. Also boats that troll offshore for sailfish for 8 hours, then gun the engine home tend to create problems from what I am told down here.
fourdfish posted 01-07-2006 02:03 PM ET (US)
LHG-- There you go again. Lets see you BACK UP your so called facts about 3500 blown power heads due to faulty VRO.
The only urban legend here is in your mind! And your purpose for trying to spread that in your posts. Since you admit to not actually having any experience with OMC, why would you
post that in the first place? At what dealer did you see all these blown powerheads? I know a lot of dealers in this area and they would sure dispute you on that one quick!
Mambo-- You are right on there!
jimh posted 01-07-2006 02:43 PM ET (US)
I find it interesting that there is an after-market replacement part for the Mercury oil injection, yet there is no such thing for the VRO. Generally people do not go into production for products that don't have a market. On that basis you might conclude there was no market for a replacement for the VRO because it works well.
Using vacuum pulses to operate a pump is a very well proven concept in an outboard motor. Just about every outboard motor ever made has a fuel lift pump which operates on crankcase vacuum pulses. I do not recall ever hearing of a fuel pump on an outboard which operates from a drive gear on the crankshaft. Is there such a thing?
Tail Chaser posted 11-15-2012 08:28 PM ET (US)
[Revived thread after being dormant for six years. Changed topic. Start a new thread for your new topic. This thread is closed now.--jimh]

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Author	Topic: Mercury 225-EFI Fuel Consumption
assaf	posted 12-30-2005 12:16 PM ET (US) I own a 1998 Outrage 21 with a Mercury 225 EFI. The motor is working flawlessly. Recently I installed a NAVMAN 2100 fuel flow meter and found some interesting facts. At idle speed in neutral gear fuel flow was not less then 2.3 GPH. At a slow trolling speed 4-MPH fuel flow was 2.9 GPH. At 6-MPH fuel flow was 4 GPH. Compare that to test data that reports an OptiMax of equivalent HP and boat that at 5-MPH the fuel flow is 0.8 GPH. [My motor shows about] four times the consumption! Is some thing wrong? At 3,600-RPM the boat speed is 29-MPH and fuel flow is 13-GPH. That is 2.23 MPG .
rtk	posted 12-30-2005 01:21 PM ET (US) I have a 1997 21 Outrage with a Mercury 250 EFI. I don't pay much attention to low speed fuel mileage, I do beleive at idle fuel burn is around 3 gallons per hour. At 3,600 RPM my results are almost identical to yours. My best economy figure at 30-MPH, around 3,600 RPM was around 11 GPH, or 2.7 MPG At a 25-MPH to 30-MPH cruise, fuel flow is typically 10-12 gallons per hour, or 2.5 MPG. When the wind or seas kick up a bit the fuel economy drops. Fuel flow is measured by the Smartcraft system. Did you ever check out the rate of fuel flow at wide open throttle? It is not for the weak of heart or pocket book. Mine is 29 gallons per hour, 48-MPH. The Optimax and EFI fuel delivery systems are very different. Rich
jimh	posted 12-30-2005 08:41 PM ET (US) I don't see any basis whereby it is reasonable to assume that a conventional port injected two-stroke engine and a direct-injected two-stroke ought to have similar fuel economy. Therefore, it is not at all surprising that the fuel flow figures reported for an OptiMax do not match the fuel flow figures you see for your EFI model.
fourdfish	posted 12-30-2005 09:14 PM ET (US) According to results I've seen the Optimax has a very low fuel consumption at idle. (.5gph or less) Of course it idles at a lower rpm than the EFI, which might might account for some of the difference. I think the higher rpm fuel consumption is better also!
assaf	posted 12-31-2005 04:00 AM ET (US) I didnt want to say that the optimax and the EFI ought to have similar fuel economy, I know they don't. but the fact that at trolling speeds and lower rpm the consumption is 3-4 times higher was very surprising to me.
dauntlass 18	posted 12-31-2005 08:27 AM ET (US) My model year 2000 200 hp Optimax on a 21ft Conquest burns about 7 to 8 gallons per hour when run in the 2800 to 3000rpm range.I base this on running the boat about 3 hours and than filling up the tank.It takes 22to 25 gallons to fill the tank.When I run the boat in the 3500 to 3800 rpm range for the same 3 hours it takes about 30 gallons to fill the tank.
jimh	posted 12-31-2005 09:55 AM ET (US) Idle speed operation is the region where the classic two-stroke motor is the least efficient. On my older two-stroke, the fuel economy (miles-per-gallon) tends to improve with engine speed. Idling along gives me worse fuel mileage than cruising at 30-MPH. The newer direct-injection motors get five or six times better fuel economy at idle speeds than port-injection motors. The direct-injection motors typically are operating in a stratified charge mode and are running very lean mixtures, perhaps on the order of a air:fuel ratio of 30:1 or higher.
assaf	posted 12-31-2005 03:57 PM ET (US) So I assume that in the real world , and not on the reported tests, the difference in the 3500 rpm zone between the DFI and the EFI, is about 25% less consumption for the DFI , am I wrong?
rtk	posted 01-01-2006 11:07 AM ET (US) While we are running around 2.5 mpg at cruise with our conventional two stroke efi engines, I have heard, or read reports that the Optimax cruise mpg is a bit over 3 mpg. Similar weight boats, lenghts and horsepower. So your 25% figure is probably not out of line for comapring fuel costs when comparing the two motors. I think 30% better efficiency at cruise has also been used when comparing the two technologies. I thought real hard about spending the extra money for the Optimax. When fuel was $2.40 a gallon the payback estimate was over quite a few years. With fuel raeching $3.75 a gallon at one point this summer, I am questioning my decision of not buying the more efficient engine. The payback comes alot sooner with higher gas prices. Over two seasons my has performed flawlessly also. Rich
aquaman	posted 01-02-2006 01:24 AM ET (US) From test reports, talking to factory reps and experience, DFI and EFI outboards fuel consumption at cruising speeds and WOT are very close. The DFI engines may have a fuel saving of less then 10%. Even the large 4 strokes don't show much better fuel ecomony then the DFI/EFI at cruising speeds. Just my 2 cents...
assaf	posted 01-02-2006 06:14 AM ET (US) Rich , if you thought fuel is expensive , in our country we pay nowadays JUST 4.55$ a gallon. Asaf.
rtk	posted 01-02-2006 03:16 PM ET (US) Ouch assaf. I started twitching a little when the price went well above $3.00 a gallon. Aquaman, I wish there was a database of Mercury reports to view. I also wish I could bolt on a 225 Optimax and see how it does. Same boat, same Smartcraft system. Your numbers could very well be reality- I honestly only have reports of individuals running the 225 Optimax, and I noticed very good fuel economy numbers for that motor. I really have no complaints on the fuel usage of my engine. If I lay off the throttle she runs pretty efficient even with a load. It is a very low maintenance engine also. Reading through the service manual there is not a good deal of maintenance to do. Very easy to service and do preventive maintenance. Rich
BW23	posted 01-02-2006 07:39 PM ET (US) I have a 97 225 EFI on a 23'Conquest running a 15P MIRAGE prop. Here are a few #'s using a Standard Hzn FF41 fuel flow meter. RPM 3600 13.5 GPH 3800 14.2 GPH 4000 15.5 GPH 4600 19.3 GPH 5000 23.0 GPH 5400 28.3 GPH
LHG	posted 01-05-2006 04:34 PM ET (US) From what I understand, none of the 3.0 liter V-6's, any brand, get very good fuel economy. My guess is that an EFI system does offer an improvement over the carbs, as I think both the Merc EFI and Yamaha OX66 do better than the carbed OMC's. A Whaler engineer told me they couldn't believe the HUGE improvement in fuel economy on a 320 Outrage when they repowered from twin 250 EFI's to twin 250XS Optimax's. He said these engines really improved the overall running qualities of the boat. And from the B&WB mag shootouts, we know the Optimax's are the fuel mileage champions of DFI's. And now the 250 Verados have even better running quality than these Optimax's
Mambo Minnow	posted 01-05-2006 05:41 PM ET (US) ASSAF, I am purchasing a 98 CONQUEST 21 with 200 MERC OFFSHORE (non EFI version). Your motor is a close relative. Can I ask specifically where your oil reservoir tank (the big one) is mounted? I know it is near the battery compartment. I need to replace the oil injection system removed by original owner. Any photos you can post would be most appreciated!
dauntlass 18	posted 01-05-2006 07:51 PM ET (US) The motor well on the 21 Conquest has a pocket molded into the well on the port side looking fordward.Every one I have seen has a flush mount fitting in the pocket similar to the fuel fill which is on the port side about admid ship.The fill fitting in the motor well has a hose attached to it and on the bottle end a screw on cap.You just unscrew the flush deck fitting and fill the bottle with a automatic trans. fill funnel .I guess 1.5 gal fills it.I am refering to the Mercury bottle which I beleive to be oem on the boat
fourdfish	posted 01-05-2006 07:54 PM ET (US) LHG-- We just went over the B&WB mag shootout on another thread about the fuel economy and yet you go back and say that the Optimax has the best DI fuel economy when you know that was not a legitimate conclusion or test for that matter. Now, I hope you are not saying the 250hp Verados have good fuel economy when absolutely no one is saying that. In fact everyone says they have the worst WOT fuel economy. And the new Verados also are showing the worst fuel economy, according to Powerboat Reports. Just another of your Mercury commercials! I guess the fact that many are turning to Suzuki is getting to you.
gss036	posted 01-05-2006 08:33 PM ET (US) MamboMinnow, before you get too deep into replacing the oil injection systems, find out why it was taken off. If the pump gears were bad, it will require a powerhead removal tear down to replace the drive gear. Really an expensive deal. Some people are going to the new electric oil systems. Just a thought.
Mambo Minnow	posted 01-05-2006 10:08 PM ET (US) I paid an independent mechanic to survey and run it...it appears original owner just did not trust system and completely removed the system and direct mixed 50 to 1. I do know to look for damage to the plastic gear wheel for oil injection and got quote of $1100 to fix that if it were bad since requires cracking the block. I have my doubts, but don't know how to inspect from the outside if gear wheel is inside the block. Any tips? Compression on all 6 cyls is good at 120 psi. Everything but the oil injection system checks out in spec. I have not heard of electric oil injection technology...any details? Sounds like might be a better retrofit option for me.
gss036	posted 01-06-2006 12:33 AM ET (US) http://www.pamlicomarine.com/msi-eoi.shtml Check out this site. They have the electric oil injection system. I have never seen one in use so I can't help out there. I am sure there is a way to look at the plastic gear w/some type of bore light inspection tool but finding one might be something else.
Mambo Minnow	posted 01-06-2006 07:39 AM ET (US) That is the most useful info I have received regarding this engine! Obviously, this must be a pretty common problem with this engine series for them to make this unit. You probably did not notice, but the site has a paragraph on how to test for oil gear failure! Many thanks for the tip!
jimh	posted 01-06-2006 09:00 AM ET (US) Mercury engines use a plastic gear to drive the oil injection pump. Failure of this gear is possible. See: http://www.outboardrepairs.com/topics/005290.html http://groups.google.com/group/rec.boats/browse_thread/thread/ 91f515ab61b262e4/71eaf2a11220a236%2371eaf2a11220a236?sa=X&oi=groupsr& start=0&num=3 http://groups.google.com/group/rec.boats/browse_thread/thread/ 90ac6ccb73b946d5/8a73df149ccc434f%238a73df149ccc434f?sa=X&oi=groupsr& start=1&num=3 http://www.biggerhammer.net/mercury/ http://www.outboardrepairs.com/topics/001915.html for some discussion of this problem.
Mambo Minnow	posted 01-06-2006 10:03 AM ET (US) JIMH and GSS...thanks for all the references. Think I will just continue to pre-mix 50 to1 like previous owner and put the $1000 into an interest bearing account for five years to save a down payment on a new ETEC or four stroke. Boat and trailer are in excellent shape. The motor appears to have been saved from catastrophic damage based on good compression and leak down tests. Motor definitely worth low end of the resale spectrum...my guess $3000 max.
LHG	posted 01-06-2006 01:25 PM ET (US) The Mercury 2-stroke oil injection system is basically bulletproof, and has been since day one. The plastic crankshaft drive gear is not a defective component just because it is plastic! If so, it would have been changed years ago, and not used on the latest blocks. Conversely, it is a successful component of the system. From what I have seen, most of the Merc or Yamaha disconnected oil injection systems are because the previous engine owned by the person was an OMC, or because the engine was raced at very high RPM of 7500 or so. There is a lot of misinformation out there. On the EFI's, you CAN't disconnect the oil injection system and it is controlled by the ECM. (at least that's what my mechanic told me). I have thousands of hours on 5 oil injected Mercury V-6's, and never the hint of any oiling problem. As the oil injection pump wears out, it actually over-oils the engine by it's design, and the oil automatically gravity feeds the engine from the engine mounted tank. When the alarm sensor module (which senses both the drive gear operation and oil level in the engine tank) is failing, is also sounds repeatedly, rather than going silent. It's a pretty good fail-safe system. If a Mercury V-6 self destructs from no oil lubrication, it's most likely the idiot behind the controls or lack of competent routine maintenance (such as oil tubing replacement on some maintenance interval)
Tom W Clark	posted 01-06-2006 02:03 PM ET (US) Larry, Your comments on the oil injection systems are substantially incorrect. All outboard manufacturers have had some failures of their oiling systems, Mercury is no exception. The original "Auto Blend" oil injection from Mercury was a disaster. The newer "Advanced Oil Injection" system has been highly reliable but not "bullet proof". The design of the Advanced Oil Injection pump has changed at least three times as the design has been improved to make it more reliable. I know all this after doing extensive research this summer troubleshooting my mechanical troubles on my Mercury 150 oil system. The OMC VRO system has the great advantage over-oiling the fuel mixture when it fails whereas the Mercury oil system failure will lead to a no-oil condition and ruin the powered. The myth of the OMC VRO unreliability has been introduced, maintained and repeated over and over mostly by you here on ContinuousWave. I wish you would give it a rest.
fourdfish	posted 01-06-2006 03:08 PM ET (US) Larry said "From what I have seen, most Merc or Yamaha disconnected oil injection systems are because the previous engine owned by a person was an OMC" When I read that, I couldn't stop laughing! That is by far one of the most ridiculous statments you have ever posted here! And you have posted some real winners! 1st You are saying that all kinds of people have switched outboard brands and then took the oil injection system off thier Merc engines that they purchased! OMG, are you lost? 2nd The OMC VRO is very reliable and I had one on my last engine for 14yrs without a single problem. So many others have had them also to make that completely false. 3rd You post without thinking about what you are writing. Tom-- I think enough people here have read Larrys posts to know whats up here! The word "substantially" is being kind!
LHG	posted 01-06-2006 03:34 PM ET (US) Tom - Wherever you are getting information on the Mercury "Auto Blend" system, it is incorrect. From the day Mercury's oil injection system was introduced (don't know the exact year), Mercury V-6's only used the integral, up to 100-to-1 oil injection system, and it has been excellent. I'm sticking by my post and my own experiences. The Auto Blend was an add-on, detached, blender box used for the 1986-1988 in-line 6's, and other smaller Hp versions of that block, and had nothing to do with the V-6's. These smaller engines were never designed for integral oil injection, and it was a stop-gap measure until Mercury caught up with OMC and Yamaha and got it's new L3 and L4 true oil injected engines out in 1989. I have no information or experience on the fixed 50-to-1 Auto Blender accessory, and don't know if it was good or bad. But I do know that when I powered my 1986 Outrage, I specifically looked for 1985 115's since they did not use this Auto Blend box, which I did not want to clutter up my transom splashwell rigging. The pre-mix 1985's made it a lot easier and cleaner. Nor, obviously, do I have any experience with the OMC VRO systems. I only know what I have seen here repeatedly, and in other places. I do know that in the late 80's OMC replaced over 3500 blown powerheads, under warranty, with the blame supposedly laid to the VRO. Maybe this OMC VRO stuff is all urban legend, or was from owner error, I don't know, and the system was perfect. But searching around CW, you will see lots of threads, by others, of their VRO problems. They continuously mention that their VRO is disconnected for some reason unknown to me. I've had no reason to disconnect the oil system on my Mercs, nor have I ever been advised to do so, nor have I had to rig up any expensive, retrofit alarm system to the engines, either. If you are going to do it on your engines as a precaution against failure of Mercury's system, be my guest, but pre-mixing 50 to 1 into a 140 gallon tank sounds like a lot of uncecessary work and expense to me. It's bad enough on my 18 Outrage 63 gallon tank
Mambo Minnow	posted 01-06-2006 04:47 PM ET (US) I can say that practices vary region to region. I have discovered here in FL from several Merc Master certified techs, I have contacted, that this FL market unfortunately has alot of cases of misinformation leading to removal of Merc oil injection system. One tech from Northeast like me, who never saw this stupidity until he came south to FL.One dealer even convinced a naive owner to remove system, when still under warranty, he could have received a no cost repair! My dad has an 84 Evinrude 90 V4 and has never had any problem with the VRO system at all in all those years. Tend to agree pre-mixing 92 gallon tank is going to be a pain, but I think I will deal w/ it until I can repower down the road in five years. FYI: The master tech had heard of the electronic system previously mentioned....apparently it was presented to Mercury for their consideration, but rejected. It seems the key to this motor avoiding failure is to not procrastinate on periodic 100 hr service maintenance. Also boats that troll offshore for sailfish for 8 hours, then gun the engine home tend to create problems from what I am told down here.
fourdfish	posted 01-07-2006 02:03 PM ET (US) LHG-- There you go again. Lets see you BACK UP your so called facts about 3500 blown power heads due to faulty VRO. The only urban legend here is in your mind! And your purpose for trying to spread that in your posts. Since you admit to not actually having any experience with OMC, why would you post that in the first place? At what dealer did you see all these blown powerheads? I know a lot of dealers in this area and they would sure dispute you on that one quick! Mambo-- You are right on there!
jimh	posted 01-07-2006 02:43 PM ET (US) I find it interesting that there is an after-market replacement part for the Mercury oil injection, yet there is no such thing for the VRO. Generally people do not go into production for products that don't have a market. On that basis you might conclude there was no market for a replacement for the VRO because it works well. Using vacuum pulses to operate a pump is a very well proven concept in an outboard motor. Just about every outboard motor ever made has a fuel lift pump which operates on crankcase vacuum pulses. I do not recall ever hearing of a fuel pump on an outboard which operates from a drive gear on the crankshaft. Is there such a thing?
Tail Chaser	posted 11-15-2012 08:28 PM ET (US) [Revived thread after being dormant for six years. Changed topic. Start a new thread for your new topic. This thread is closed now.--jimh]