posted 09-24-2012 07:35 AM ET (US)        

Over Labor day weekend I headed out on what was suppose to be a weekend of fishing... But thanks again to one of my "Optibombs" the trip was cut short...

This time, bearings on the air compressor for my starboard motor went bad. So three hours into our trip we had to turn around and idle on back to the dock on the port side engine. Up until the compressor bearings died, both motors were running strong.

Instead of replacing the bearings, I purchased a new compressor. Do to other things going on in life, I finally got around to installing it this past Saturday. I read up in the Merc shop manual about replacing the compressor and thought it looked pretty much cut and dry.

However, after installing the compressor, the motor was difficult to start. When I finally did get her to run, I discovered she was only running on cylinders 2-4 and 6.

After checking for blown fuses, disconnected or loose wires, I checked for spark and found all three cylinders were firing. I then disconnected the control wires for the fuel injectors on cylinders 1-3 and 5. Disconnecting all three injectors at the same time made no difference in how it ran.

The fact that my port engine runs fine, I swapped the compressors to see if the trouble followed the compressor. It did not. Then I switched the ECU to see if it was failing to send signals to the cylinders, but again the trouble did not follow the part. I'm now assuming that I have trouble with the port side fuel rail.

Has anyone ever experience something similar? I can't imagine that I had three injectors all go bad at the same time. Remember that motor was running fine until the compressor bearings went bad.

posted 09-24-2012 11:03 PM ET (US)            

By any chance do you know how many hours you got out of that compressor before it blew? Mercury offers a new design on this part in hopes to eliminate this problem. The other designs are really no different that the others with minimal change. Apparently this new one offers a bearing on each side rather than the one giving it needed support from possibly movement. They are not cheap quite cheeky of the company imo to ask the price they do considering they know this has been a problem part.

Martyn

posted 09-24-2012 11:13 PM ET (US)            

I think its an assembly problem and perhaps instal at the factory. The part needs to be precise engineering. Its interesting how Mercury has put a stop to this part being built in Mexico after all these years and now is mandatory to being assembled in the US only!

posted 09-25-2012 07:10 AM ET (US)            

Thanks for your assistance... I assumed I was going to have to disassemble the fuel rail...but hearing it from others confirms my suspicions and makes me feel more comfortable before diving into another morning of repair work...

Reading my shop manual, the 1997 engines had a filter screen on the high pressure side of the compressor to catch the filings before they got to the fuel rails. I thought that was a good idea, but of course Mercury thought they could save a dollar...

Martyn,
The compressors only had 480hrs on it... not exactly bullet proof as far as I'm concerned... I love the boat but dislike the engines... I'm investigating what it will cost to re power with Yamaha or Honda four strokes... Unfortunately for Brunswick, I have zero confidence in their engines.

posted 09-25-2012 03:29 PM ET (US)            

I have the the newer versions of your engine but it doesn't necessarily mean I'm going to get away scotch free. I have 344 hours. I am keeping a close eye with people who have installed the new design compressor to see if it actually makes the difference. If it does, I might actually replace my current compressors before the 500 range as more of a preventive maintenance procedure. It would cost about 2k for the parts alone but if it gets me another 1500 or more hours of blow up free time it might actually be a good investment. New engines are 20K or more each. If the compressor blows and tears apart my engine I might be faced with a $3k clean up bill or more on the aftermath of the bomb. Its the lesser of the two evils for me. I second your vision of the Honda or Yamaha. New discussions here on CW in regards to the Honda 250 is quite positive on reliability and gas savings.

posted 09-27-2012 07:58 PM ET (US)            

I may have caused some confusion with my original post. The compressor did not explode. What failed was the bearing. What was strange about the failure was the outer race of the bearing became loose in what Mercury calls the "end cap". It almost appears as if the bearing seized and the torque from the drive belt spun the entire bearing assembly in the aluminum "end cap". After a few rotations it ate away at the aluminum allowing the bearing assembly, including the drive pulley to flop back and forth. Which was the cause of the noise I heard from under the cowling. I will be disassembling the old compressor and report on what I find. It sounds like the bearings will simply fall apart in my hands.

posted 09-28-2012 01:37 PM ET (US)            

I am really curious, how would you best describe the sound of the noise you heard in the engine? Was is a wheezing sound or high pitch noise or just clicking? Did it get louder when you were running higher rpm's or was it continuous even at idle. I have one engine in the twins that is making a slight noise more distinct than the other. I can't really confirm that its a wearing pre failure to the compressor but Im really conscious about it for the obvious reasons. I have only 344h hours on mine at the moment but they run great otherwise. I talked to a mechanic who told me to relax they are all different and no two engines sound the same and that it was harmless at this point.

Thanks,

posted 09-28-2012 05:31 PM ET (US)            

The cylinder walls became scuffed and some aluminum was discharged into the airline for the fuel rails. Also, the roller bearings on the connecting rod (at the crank end) had it's outer race crack. This weekend I hope to get to the boat and disassemble the fuel rails, clean out any debris that may be clogging the injectors and get this engine running again.

posted 09-28-2012 05:56 PM ET (US)         

Where would you be if the boat came with OMC manufactured 1999 Evinrude Fichts, before bankruptcy? They are all in the scrap heap.

posted 09-29-2012 12:45 AM ET (US)            

Larry the other problem is they die at anytime sometimes 8 hours only some go at 200 but most are in the 500 range from what I have gathered. Estimated time 5 years? I guess if you are lucky Mercury will cover it but once out of warranty that part is a time bomb and it shouldn't be. In fact sometimes the part is replaced and then dies again!

posted 09-29-2012 06:40 AM ET (US)            

Not sure what your point is, but I have had tractors with 600,000 + thousand miles on them and never had an AC compressor go bad. And my AC compressors are exposed to all sorts of highway dirt, salt and grime. Not to say that AC compressors don't eventually wear out, but come on, do the math and figure out how much longer they last...

Not sure where Mercury has these compressors made, but 480 hours on an air compressor? And these units are lubricated with two stroke oil and water cooled? Give me a break...

I'm not concerned about Evinrude Ficht's... Never owned one, but if I had, I'd be just as upset...

Before these Mercs, I owned Johnson's. And sorry to say Larry, I never had one self implode like these black Pieces Of S*#$!!!

Nothing like being on the water and WITHOUT WARNING have a piston and cylinder get wasted... I've been trying to keep these "Optibombs" from going to the dump for the past 6 years. I've had to resurrect each engine from the dead once. Apparently I rebuild these engines better than Merc makes them from the get go...

"Mr Mercury", you are correct about one thing, these engines are worth nothing. Having them bolted to the transom is actually detrimental to the value of my 1999 Boston Whaler 280 Conquest...

My 1990 Boston Whaler Revenge 22 W/T has 1999 twin F100 Yamaha's on her transom. Would you believe I have yet to do anything but change the oil and filter, gap the plugs and replace the zincs. Go figure...

I'd be willing to bet if I had Yamaha's or Honda's on my Conquest I would not be having this literary exchange with you...

posted 09-29-2012 11:11 AM ET (US)            

The program was not widely known, and I think the dealers were not keen on it. I asked my local Mercury dealer about it, and he pooh-poohed it. I think he would have rather sold a new engine at full cost than a factory second-tier engine at a reduced cost. Of course, my local Mercury dealer advised all his customers not to buy any OptiMax engines, so he was not likely to recommend buying a factory-rebuilt one that has blown up under warranty for another customer.

posted 09-29-2012 08:12 PM ET (US)            

MERCURY???

Only if I were marooned on a deserted island would I ever consider having a Mercury on my boat...

posted 10-01-2012 02:10 AM ET (US)            

4200 hours is just amazing for sure I would hope there are many more of them personally but you only here about the bad things usually why because people are mad disappointed and frustrated looking for advice its normal because we expect them to work all the time or at least most of the time. If they are breaking down while other engines are working at same hour intervals it adds to the frustration. Owners like Revenge Family have genuine concern with certain parts that are problems. There is a new fix for this Im just not sure its a bit early to really give it full praise but I would say if you have a good running Opti this part although expensive could very well be something that could eliminate a nick name given the Optibomb for good. Yes for good or at least cut the odds down. 13 years seems like a long time but I always base an engine on hours as long as the there is no corrosion inside these parts are based on usage. 480 is nothing its like a baby for a modern day engine. Can we expect them to last without compressors blowing up? I think so and I would expect that Mercury team would also agree they should.

The Optimax is rated for I think 2000 hours on the powerhead? These parts should be trouble free for longer than 500 range. If they don't on average then something is wrong. Also keep in mind the newer the Opti the more updated parts are factory installed years of learning the hard way have been adapted to eliminate problems that have plagued this motor. Im not letting Mercury off the hook with the early ones they should be better at 500 hours but it is the truth sadly and many have been caught in between which once again upsets the client in thinking they may have invested in a bad engine.

posted 10-01-2012 05:13 PM ET (US)            

If every time a certain topic comes up there is a certain person who jumps in with his first-hand experience, then I suppose that long-time readers might begin to recognize a trend.

posted 10-01-2012 09:19 PM ET (US)            

Do you own stock in Brunswick?

You must be delusional... You can't honestly think that I'd rather be at my computer asking for advice about repairing what YOU believe to be a fictitious problem?

Trust me when I tell you I'd rather be out on the water using my Whaler... Especially if the "Optibombs" would get me to and from a deserted island...

posted 10-01-2012 10:54 PM ET (US)         

1. I have never owned Brunswick stock

2. I don't have any money with Bain Capital

3. I have been smart enough to not buy 1999 DFI engines, either by Mercury or the old OMC.

4. I have told many privately, upon asking, that I would never own a DFI engine produced before 2004. That includes both Optimax and Ficht.

5. I have a pair of EFI Mercurys, 1997 year models bought new, that have been around 2500 hours on them, with no problems at all, other than non-powerhead related maintenance and wear and tear replacements. (I had a non-warranty power trim motor fail, and I didn't blanket this site with complaints about sub-standard Mercury parts) They are both quieter running and more powerful than those early Optimax engines, and get pretty good fuel economy.

http://smg.photobucket.com/albums/v429/lgoltz/Outrage%2025/?action=view& current=MVI_0147.mp4 Why would I need to replace them?
But if I need to, I will.

posted 10-06-2012 08:24 AM ET (US)            

After having my air compressor go bad back in September, I was certain that parts of the compressor had found their way into the fuel rails, so I concentrated my efforts there.

Not sure why, but I do my best analogical thinking early in the morning... Earlier this week at 03:40 I was going through my engines dilemma when something I had read in the shop manual was resurrected in my head. I remembered reading that when shifting, three of the fuel injectors are momentarily shut down to give the motor a bit of a "hiccup". This allows the gears in the lower unit to shift smoothly...

This momentary shut down of the three fuel injectors is controlled by a micro switch on the port side of the engine block. What are the odds that after my compressor died, the micro switch also got stuck in the electronically open position? I believe this would keep injectors 2-4-6 shut down.

So back to the boat today to inspect the switch... Will let you know what I find.

posted 07-07-2014 07:39 AM ET (US)            

Unfortunately (but good for my wallet) I'm getting pretty good at diagnosing problems with these engines. Using the quick disconnects on the fuel and air injectors is a good way of identifying sick cylinders on the Optis.

I sent all six air injectors out to be cleaned and discovered that two were no longer serviceable. I knew Mercury charges an arm and a leg for them but went to the local dealer who said with a smile on his face that each air injector was only $385. I told him to go *#&# off and ended up purchasing used injectors on ebay for around $100 each. You see, there are so many of these POS's failing that guys are parting them out.

Keep in mind that this was a minor disaster for this motor and occurred in September of 2012.

Labor Day 2013 this engine seized on me again. This time I discovered the mighty "O" ring that Mercury uses for head gaskets on each cylinder split on cylinder 6. This allowed water to wash the cylinder wall and eventually seized the engine again.

So again I rebuilt it and am loving my Boston Whaler 280 Conquest but I'm still apprehensive to go more than 20 miles from the marina because I can never tell when the next Mercury Optimax disaster will occur.

posted 07-09-2014 01:49 AM ET (US)            

I agree with Martyn, these engine can be very solid provided the owner pays close attention to diligent maintenance. Unfortunately, my experience is that most owners do not really have the time or desire to pay that much attention to service. The latest four-stroke engines are probably more user friendly and therefore may turn out to be superior in terms of satisfaction of the overall owner experience. As to pure power and performance, the DFI two-stroke engines can certainly hold their own in that department.