2004 Optimax 115 for 72 Seafari 20
 

Happy New Year!

Found a 2004 Optimax 115 for fair money w/ smartcraft controls/gauges. 350 hrs.

Questions:
1. are my rotary ride-glide steering and Commander controls compatible with the Opti?

2. does the usage printout show break in chronology or just hours at each rpm range?

3. general opinions on the year or motor model?

4. What is fair price range for such a motor?

Thanks!

Re: 2004 Optimax 115 for 72 Seafari 20
 

Great find! Your controls and steering will work just fine. You may need a new key wiring harness, though. I don't think the cannon plug connectors are the same.
I don't recall what the difference was, but when I bought my 90 Opti, I had to specify whether I wanted a SMARTCraft version of the engine, or mechanical/analog version. I chose the manual control version. (The SMARTcraft engines actually say SMARTcraft on the back of the cowling in '06)
So if this 115 was being run with SMARTcraft controls, you may have to do something to convert it. I'd ask Tim about that. (Bigshrimpin).

A quick search on Craigslist and ebay found 6 Mercury 115 Optimax motors between 2003 and 2007 model years. Lowest asking price was $3150 for an '05 with over 1000 hours on it. Highest asking price I found was $5300 for an '07 with under 100 hours.

NADA says $3130 avg. retail for an '04 115 Opti.
BoatUS says $3370 avg. retail for an'04 115 Opti 20" non-power steering with a saltwater history, $3510 for a freshwater motor.

So, (going out on a limb here), $3,000 to $3,500 is my guess.

Re: 2004 Optimax 115 for 72 Seafari 20
 

Thanks for the input, Fr. Frank.
Happy New Year! May the dawn of a new decade bring grumpy grouper and plenty of water time.

Price is right between the NADA/BUS numbers you mentioned.

I have a call in to the resident Merc Wizard of MA and CSC.

A few more questions for you when you have the time:

Is your 90hp a 20 or 25" shaft. How does she sit(wet feet without plugs) in the water?

Did you move batteries forward? And what are you using for a starting battery - my understanding is that these motors require 1000 MCA or 750 CCA?

Do these motors really sip the gas at trolling or idle and lower "hunting speeds" (say 2500 to 3500rpm or 15 to 22 mph). I've heard silly stuff like 8-9 mpg at 1000 to 2000 rpm... T/F?

The irony is that this motor is currently on an SF20 that I nearly bought in 07 when I found my Seafari. Almost bought both at the time just to get the boat and motor that I wanted...Present owner is looking for a 175 hp class Merc, like an XR2 or an XR4.
Full circle, baby...
:cool:

Re: 2004 Optimax 115 for 72 Seafari 20
 

My 90 is a 20" shaft.

Yes, if I take out the deck drain plugs, my feet will get wet.

For a starting battery I have a single group 29. I used to have two group 24's, but twice I had trouble starting because of the lack of amperage. If you don't have the juice, the motor spins, but no fire.

My battery is in the original battery box at the starboard corner of the hull and transom below seat hatch. It just barely fits because of it's large size.

According to my mechanic, his reading of the computer says that at 1200 rpms (about 4.8 mph) I am burning about .65 gallons per hour, or about 7 mpg, not the 8-9 mpg others have reported. On the other hand, I get just over 5 mpg at cruise of 24-25 mph and 4500 rpms.

I fall off plane at about 19-20 mph and 3500 rpms, even trimmed down. I really need trim tabs.

Re: 2004 Optimax 115 for 72 Seafari 20
 

From experience - if you don't have 900 cranking amps available the computer on the Opti will not allow it to fire. As FrFrank said - it will turn over but not fire. You have to have a good cranking battery. And if you plan to anchor and fish offshore, make sure your cranking battery is isolated from your "other stuff" battery. Trust me - that other stuff will draw the battery down enough to prevent the Opti from firing. Been there, done that, been helped in.

Re: 2004 Optimax 115 for 72 Seafari 20
 

are you kidding me i would look into a different motor i don't know i would trust it drifting around rips or night fishing are all new motors like that :D

Re: 2004 Optimax 115 for 72 Seafari 20
 

Thanks again, guys.

Sounds like I better start saving for trim tabs and reconsidering the "vortex."

When I re-wired I set-up separate "starting" and "house" batteries using a Blue Sea Systems ACR/SI ("add a battery" unit). I've been very pleased with the system thus far. I'm ready for a new starting battery anyway, so that $170 upgrade is accounted for. If I get this motor I'll probably go with a Deka group 31 AGM. Or whatever offers 1000 cranking amps.

Required starting amperage aside, are there other concerns about the 115 Optimax?

I tend to think I can keep my old steering, but the motor comes with its own ignition harness so I imagine that changes out.

Does anyone know if my old Merc Commander shifter controls would be compatible with the Optimax?

Thanks again.

-Gillie

Re: 2004 Optimax 115 for 72 Seafari 20
 

The Optimax uses the same Merc control cables that have been around for 52 years. So yeah, your MerCommander controls will shift and move the throttle.

BTW, since going to a group 29 battery, I have had no problems with the Optimax starting. My group 29 battery says "965 CCA". The battery I have hooked to my diesel generator at home is much bigger, and says "1475 CCA". It weighs 120 lbs, though. With my twice-rebuilt back, I can't move it without a shop crane, otherwise I would have used it. :D

Re: 2004 Optimax 115 for 72 Seafari 20
 

I did learn this the hard way - my Merc mechanic learned me up on it when I took it in to him after being helped back in. This was a 1999 200, so maybe something has changed in 11 years. I have different boat and a 150 ETEC now with two batteries with a Perco switch. I don't know if it has the same cranking amp requirements as the Opti, but I am cautious anyway. I start on battery one and head out. When I get to my fishing grounds, I switch to battery 2 to anchor, troll or whatever. Runs radio, GPS, bilge pumps, baitwell, etc. Then I have battery one ready to crank at full charge again because it charged all the way running out - sometimes a two hour run. If battery two won't crank it to head back in, I can crank on battery one, then switch to "both" and run back in, charging both batteries. I also have an on-board charger system and I charge both of them the night before I head out.

But - to be honest, I have never had a situation where either battery would not crank the ETEC, even after a day of fishing. Maybe I am over-cautious with what I do, but I sure don't want to be stranded again. Maybe someone else knows the ETEC requirements? I can't find anything in my owners manual that covers it.

Re: 2004 Optimax 115 for 72 Seafari 20
 

One of my 2 batteries has been weak for last year or so and never comes up to more than about 50% of max capacity, I think about 12.4 volts, unloaded. I always run on it and keep the other one in reserve. My E-Tec always lights off within 1 revolution with the weak battery. I think it's started down as low as 12.1-12.2 volts; can't remember exactly, but it's never failed to start.

Re: 2004 Optimax 115 for 72 Seafari 20
 

I try to go out on #1 and come back on #2. This way I hope to charge both equally. I just pulled the charger off #1.
Cycle your charging and replace in pairs.
Cheers,
GFS

Re: 2004 Optimax 115 for 72 Seafari 20
 

That's interesting how efficiently the E-tec winds up especially compared to the Opti, Denny - wonder if it has to do with the power required to run the Opti's injection compressor??? Wish I could find a 4-5 y.o. e-tec for this money...Even my I-6 won't fire with less than 12.3V or so...

Even so if that battery of yours is past 50%, you better hit the retirement plan for a new battery before your next circumnavigation ;)

Ron makes a good point about isolating your starting battery. The Blue Sea Systems is neat (and it sounds like a few of you guys might consider it -this means you Sandman ;) ) in that the switch is "on," "off," or "combine," and when "on," it charges both batteries while you run.

Say battery A is dedicated to starting and battery B is "house battery." They are isolated circuits but in the "on" position, both circuits charge simultaneously while running.
the auto charging relay measures what circuit needs more juice and cuts and distributes it accordingly.

The only time you "combine" the batteries is in the case of emergency starting wherein your starting battery has failed (bad cell, neglect, whatever). Diodes in the ACR and isolation keep bad battery from draining the still good battery. The ACR even measures and detects voltage to keep from overcharging and defers excess charging to the weaker battery. The isolation also eliminates sags and spikes to electrical equipment when starting motor. I love the effective simplicity. Here's the link if you want to check it out. http://bluesea.com/category/2/productline/overview/329

Re: 2004 Optimax 115 for 72 Seafari 20
 

[QUOTE]
That's interesting how efficiently the E-tec winds up especially compared to the Opti, Denny - wonder if it has to do with the power required to run the Opti's injection compressor??? Wish I could find a 4-5 y.o. e-tec for this money...Even my I-6 won't fire with less than 12.3V or so...

Even so if that battery of yours is past 50%, you better hit the retirement plan for a new battery before your next circumnavigation ;)

Ron makes a good point about isolating your starting battery. The Blue Sea Systems is neat (and it sounds like a few of you guys might consider it -this means you Sandman ;) ) in that the switch is "on," "off," or "combine," and when "on," it charges both batteries while you run.

The Sea Tow call was fuel vacuum. Bulb clamp sneeze by. Defective as new , but worked for a month.

The primary wiring is pretty clean, but the house is calling.

That`s a neat system and you know I dislike wiring more than working on my trailer. It is also why I have reservations about making the crossing.

Time to buy a mini torch. A good owner should know his wiring is right.
Cheers,
GFS

Re: 2004 Optimax 115 for 72 Seafari 20
 

Today I think I found the lower limit on battery voltage for my 150 E-Tec to start! Boat has been sitting for about a month since last run. Voltage on my old No. 1 battery was 12.07 volts, and it didn't light off on first revolution like it normally does! (Took 2 revolutions! :eek:)

A typical battery capacity chart says 12.1V = about 25% of capacity, so looks like that's about the lower limit for a successful start. Battery is a group 27, at least 5 years old; don't remember CCA rating, but it's at least 600, more likely 700-800. Might be able to go a little lower on starting voltage, but probably not very much. This battery is definitely ready for the recycle bin! Will replace it as soon as I finish bottom painting project. Denny

Re: 2004 Optimax 115 for 72 Seafari 20
 

An onboard charger is the best thing I did for my batteries. Just leave it plugged in on the trailer.

http://www.marinco.com/product/10-am...epro-charger-0

Re: 2004 Optimax 115 for 72 Seafari 20
 

Hey reelescape-
Did that charger come with cables or did you have to make them up yourself?

Re: 2004 Optimax 115 for 72 Seafari 20
 

basspro has a 10 amp dual bank on board charger on sale for $100. 2 year warranty also. i just picked ut up for the 20. havent installed it yet.
reelscape, you dont worry about it frying your batteries??

Re: 2004 Optimax 115 for 72 Seafari 20
 

It comes as pictured including fuses. I mounted mine on the inside of door near batteries with receptacle facing outward. Remove rubber cover, plug in extension cord. The unit is waterproof.

Blue.....it only charges when needed. It switches on/off internally. Now if the unit failed.......

http://img.photobucket.com/albums/v6...1/DSC_0290.jpg

Re: 2004 Optimax 115 for 72 Seafari 20
 

have those batteries been good to you? im thinking of gettin them when my other ones go bad. what group are they?

Re: 2004 Optimax 115 for 72 Seafari 20
 

I replaced them since the picture. I bought Optima blue tops.

Re: 2004 Optimax 115 for 72 Seafari 20
 

When I bought my Opti (175), I was told to get at least a 1000 CCA battery. Not sure if its the same for a 115. Ask the current owner, it will be in the owner's manual.