posted 07-16-2005 07:55 AM ET (US)        

I just got my 23 OUTRAGE with twin 150-HP Mercury OptiMax engines that have 250-hours of use. All normal maintenance has been done at the dealer. Plugs. Foot. Oil. Water pumps. Owner kept good records.

posted 07-16-2005 10:20 AM ET (US)            

http://outdoorsbest.zeroforum.com/zerothread?id=369048

I hope your experience is better. Many have reported strong performance from this engine. The fundamental block is a strong performer and with carburetor or fuel-injection systems these same engines have outstanding records.

As you may know, Mercury was forced into a settlement of a class-action lawsuit against them brought by owners of OptiMax engines.

posted 07-16-2005 01:40 PM ET (US)            

1. Use Optimax DFI oil. Buy in bulk from a dealer in your own containers and it's reasonable.

2. Change water pump impeller, fuel filters, plugs, clean compressor filter, and change lower unit oil every season (no matter how few hours you use it).

3. Check all belts every season for wear and replace as needed.

4. Use only a 1000 MCA (800 CCA) starting or dual purpose battery. Change every 2 years.

5. Run Mercury Quick Kleen in your gas periodically to help in minimizing carbon buildup. I do it every 2 or 3 tankfulls (between 500-800 miles on the GPS).

I own the Opti 135 (twins) and have had the same engine on my last Whaler. I bought my newer boat with this engine because of my past experience. My contacts at mercury tell me they are extremely reliable with regular maitnenance.

posted 07-17-2005 04:49 PM ET (US)            

I am a bit curious to know if it actually says that. The Mercury maintenance manual for the 150-HP Optimax c.2000 just says the following:

"Recommended Battery
A 12 volt marine battery with a minimum Cold Cranking amperage rating of 750 amperes or 1000 (minimum) Marine Cranking amperes should be used."

Perhaps they have changed their specifications.

A deep cycle battery with a rating of 1,000 MCA may be harder to find than a marine starting battery with that rating.

The general impression of the OptiMax engine is that below a fast idle speed, say 1,000-RPM, the engine is a net consumer of current. That is, it needs more current to run than it can generate from its charging circuit, therefore it is draining the battery at those speeds. It also appears that these engines are very sensitive to voltage, and if the supply voltage drops much at all below 12-volts, the engine will not run properly. This is probably why they specify such a huge starting battery for them. They need to have a stiff supply of 12-volts to get started and running and idle speeds.

The Optimax engine has a lot of electrical devices. It has electrical fuel injectors AND electrical air injectors. It has twice as many injectors as other fuel-injected or direct-injected engines. And it has an electrical fuel pump (which all fuel injected engines tend to have because they have a pressurized fuel rail).

Because you are using your OptiMax for trolling, you may be running it close to the point where its charging current and its electrical demand are about equal. It would be interesting to actually measure the charging current at your favorite trolling speed.

In any case, stick with a strong battery and you will avoid problems. The principal job of the battery on your boat is to start the engine, so I'd get a battery that was designed for that job as my primary battery.

posted 07-18-2005 07:59 PM ET (US)            

prm177
My 170 came with an interstate 24mxhd 800cca 1000 mca Marine rv cranking battery so if its listed elsewhere as a dual purpose battery it seems to make sense to use the same one as my second battery.

Whalerider
I wish we had Cabelas out here. I get the catalogs but its not the same as having a store nearby. Thanks for the information, I need to get a good book on marine electronics, probably one of those for Dummies books.

posted 09-17-2006 03:48 PM ET (US)            

I have a 2001 Mercury Optimax 150 Hp with 500 hours of use.
After having my boat in a garage for one week, I start it and remark that it stalls and coughs at idle speed,and stops running after less than a minute. That repeats over and over again. Once over 1200 rpm, the engine runs O.k.
We check and clean the 12 inyectors, we put 6 new candles and a new coil (all original), as well as a new fuel filter. Another checking discards fuel escapes and electric problems.But the problem remains the same, rpm are very ustable at idle speed. We take the engine to the local dealer for a computer-assisted diagnostic. apparently everything is ok for the computer. But the engine keeps running badly. We check the mechanical fuel pump (OK) and take the boat to the water. From 1200 rpm on it runs as if it was perfect, (til 5250 rpm) but after half an hour we notice that it makes it difficult to get over 4500 rpm. In any case, we don't observe any other anomaly running at high rpm.
We have also measured the fuel pressure (70 PSI) and the air pressure (60 PSI). We know that these results are under the normal parameters (over 80 PSI for fuel pressure) but we don't really know where the problem is, as the fuel pump (with less than 100 hours) apparently works good.
My local dealer doesn't dare to change it (maybe a lot of money for nothing) and have no idea about the problem root.

All information on this subject will be very welcome.

thank you in advance for your effort

posted 09-19-2006 06:11 AM ET (US)            

One more thing, what do you mean by "guage"? Are you referring to the device which is used to measure pressure?
I have the service manual, and according to it I shoud be reading 87 +-2 PSI as fuel pressure, with a difference of 10 PSI in comparison to air pressure (which should be then 77 +-2 PSI). When the engine is running, pressure keeps the same all the time(70 PSI for fuel pressure, 60 PSI for air pressure),it doesn't fall down, but it doesn't reach the optimal levels. Does it suggest too a pump problem?
I don't want to bother too much , but I'm really interested in knowing your opinion on that.

posted 05-14-2007 02:17 PM ET (US)            

- Erratic speedometer. Speedometer jumps around when I'm running

- False Alarms like "Check Paddlewheel"

- False Alarms like "Check Pitot"

All these problems completely disappeared after putting in a fresh pair of batteries. Now I replace them every 2 years with the same Interstate models. This time I'm going to see if I can squeeze in a pair of Interstate 27M-XHDs

posted 05-29-2007 08:42 PM ET (US)            

I recall seeing something like this in an older Evinrude engine. The problem was something called a power pack, but generally when these failed, there was no spark to any cylinder, not just some but not others. I just don't know enough about these newer electronic-based engines to know where to start. (And obviously am concerned that a service department is baffled on this one. My doubting side is wondering whether someone has connected something up incorrectly and damaged something, and they're now looking for a way out at my expense.)

Anyone got any ideas, or know what might be causing this?

posted 05-29-2007 11:10 PM ET (US)            

I am somewhat familiar with OMC ignition systems and their power pack, and it is possible that there can be a failure in a power pack which affects only one cylinder. I just went through half a boating season chasing an intermittent spark problem in just one cylinder of my engine, eventually curing it with a new power pack.

posted 07-13-2007 12:49 PM ET (US)            

Now that the check engine light is on, it could be a bad (weak)coil, sensor, etc.

What are your thoughts?