2003 200 hp Opti loses 500 RPM when trimming, won't go above 3000 RPM now

[Ogreman51]

Hi all. New member here, so be gentle! I just purchased a used 2003 200 hp Opti (Saltwater) in the last 2 months to replace my old Blackmax on my fish and ski. The motor looks to be in great shape, despite the salt water usage which wasn't that many hours. My mechanic and I hooked it all up, and when I test ran it for the first time on the lake a week ago, it ran great! Just like a scalded dog! Wonderful acceleration with no hesitations, beautiful up on plane right away, got 5400 rpm (just right) on the prop I installed at full throttle. Max speed over 50 mph (plenty for an old guy like me!) Anyway, I took it down to Amistad near Del Rio on a fishing trip the day after for 3 days. The first day, it ran perfect, no problems. Second day, things started happening. First off, when at FOT, I began to notice a very jolting drop in RPM (500, or so) whenever I would hit the trim switch. Didn't know what to think, but since I pretty much need to have the motor trimmed full down anyway, I decided I'd worry about this later and try to enjoy the fishing. So that went on till late in the afternoon. THEN, the next thing that happened is my top-end RPM began to be limited . . . I couldn't get above 3000 or so RPM. AND, at low RPM, I noticed the engine sounded like it was missing a bit and definitely NOT running with the smooth raw power that I'd noticed when I first ran it. I've looked on line at various places, and a number of people seem to think that this sort of thing is what happens with either bad battery connections, a bad battery itself, or perhaps a bad alternator (ie, all electrical problems). Haven't visited with my mechanic about this except a brief telecon, and he says maybe water in the gas. I DID find out that the battery is at the end of it's useful life (O'Reilly Auto Parts tested it and said it was pretty much toast, so I replaced it with a new Marine battery with 1000 CCAs). I ALSO noticed that when I took the old battery out, it was just a bit of a loose connection on the + terminal (yep, I use wing nuts - I'm not gonna make that mistake anymore though . . . the new battery has stainless steel hex nuts). And to top it off, I also realized that somehow, I DIDN'T have the main cable from the alternator on the bottom of the stack on the positive terminal ofthe battery. I've since gleaned from on line that this is also a Romper Room no-no. A local Merc dealer who looked at the boat for me for about 5 minutes also said that the fuel line I currently have is a bit pinched and is NOT a MERCURY fuel line, so I'll probably replace the fuel line, as well. I may even bore a separate hole for it thru the lower cowling, since it appears all my cables in the cable bundle are kind of compressing the fuel line some. So, before I go out and buy a whole new alternator to boot, would anyone care to chime in? I welcome all comments. Thanks! Mike

[Savage]

Why do you want to change the alternator? You already diagnosed the bad battery.

[Ogreman51]

Not sure I DO, Savage! Is there a simple way to test the alternator though?

[lpugh]

[Savage]

Yes with a DVOM on the big red lead coming from the alternator.

[SilverFox579]

Yes, measure voltage at the battery using a DMM with engine running. What battery did you get (specific brand and model)? There's a great topic in the FAQ at top of forum about batteries you should take the time to read.

Savage snuck that in while I was typing. Either location will work but at the alternator eliminates the cable to the battery (which could be corroded or have bad terminals). You should see essentially the same voltage at the alternator and battery positive.

[Ogreman51]

Anybody put any worth into what the dealer told me about possible pinched fuel line causing the kind of problems I've had?? Thanks.

[Ogreman51]

Ok, thanks guys! I'll check it out with the meter. Ya know, I DO have a new Smartcraft Tach which was giving good voltage info while everything was running well. But when the motor starting acting up, I just got so distracted by the bad sounds and poor performance, I didn't look at the volt meter (dumb) on SC. If there WERE electrical problems, it probably would've been reflected on the LED readout for volts on the Tach. Guess I was just too intent on getting out of the water without paying enough attention to my gauge readings right there in front of me. Live and learn.

[Ogreman51]

SilverFox, to be honest, I don't know the brand of battery I got. I just know that it shows 1000 CCA, which is what Merc recommends. I got it thru exchange for the old one at O'Reilly's Auto Parts, but I do know it's a Marine battery. If I remember to do it, I'll check the brand and let you know. Whatever, it is, it comes with a 12 mo warranty. Thanks for the comments.

[Savage]

You need to fix the obvious problems FIRST, then re-test and see how it does. A bad battery can cause a multitude of running problems.

[SilverFox579]

You need to fix the obvious problems FIRST, then re-test and see how it does. A bad battery can cause a multitude of running problems.

+1.

What group size is that O'Reilly's battery? Make sure it actually has 1000 COLD cranking amps which is not the same thing as MARINE cranking amps and it matters with an Optimax. Voltage test must be performed with a DMM at the battery or at the alternator, not by a dash gauge or sonar reading.

[Ogreman51]

Thanks Phil. Haven't done the DMM TEST at the alternator or battery yet, but i will.

[Ogreman51]

Sorry y'all. I forgot, per guidelines, the Serial # is OT 795401. 2003 Optimax 200 Saltwater. I have another issue: I am getting 2 warnings on my Smartcraft Tach. 1) low oil level. 2) low fuel level. I replaced the oil probe in the mini-reservoir which I hoped would solve this problem. It didn't. Also, the low fuel level warning won't go away. I'm assuming that in the case of the oil, perhaps there's a way to calibrate the SC tach to ignore the oil level? The oil level in the reservoirs visually show full, and I have good air pressure in the main oil tank, so there is NO problem with the oil, other than this warning. Or, perhaps something isn't hooked up properly? In the case of the low fuel warning, perhaps it, too, can be "calibrated away" thru the SC tach? Or do I need a separate digital fuel sensor for the fuel tank? If so, does anyone have a part number which will work with SC technology to register oil/fuel readings on the SC digital readout? Comments? Thanks.

Phil, there is not a name brand on the new battery I bought. I got it at O'Reilly's Auto, and it just says it's a Marine Starting battery with 1000 cca. Not sure what you mean by group size. Thanks.

[EuropeanAM]

Sorry y'all. I forgot, per guidelines, the Serial # is OT 795401. 2003 Optimax 200 Saltwater. I have another issue: I am getting 2 warnings on my Smartcraft Tach. 1) low oil level. 2) low fuel level. I replaced the oil probe in the mini-reservoir which I hoped would solve this problem. It didn't. Also, the low fuel level warning won't go away. I'm assuming that in the case of the oil, perhaps there's a way to calibrate the SC tach to ignore the oil level? The oil level in the reservoirs visually show full, and I have good air pressure in the main oil tank, so there is NO problem with the oil, other than this warning. Or, perhaps something isn't hooked up properly? In the case of the low fuel warning, perhaps it, too, can be "calibrated away" thru the SC tach? Or do I need a separate digital fuel sensor for the fuel tank? If so, does anyone have a part number which will work with SC technology to register oil/fuel readings on the SC digital readout? Comments? Thanks.

Phil, there is not a name brand on the new battery I bought. I got it at O'Reilly's Auto, and it just says it's a Marine Starting battery with 1000 cca. Not sure what you mean by group size. Thanks.

Thanks for providing the Serial Number.

Let's go through things methodically, one at a time. Come back to the ones that aren't critical at this point.

Battery: I am skeptical that the battery you bought at O-Reileys was a 1000 CCA. I suspect it was 1000 CA or MCA. BIG difference in those ratings.

1000 CCA would be good for your application. The others- meet the BARE MINIMUM capacity for the engine alone (without boat accessories added).

VERIFY THAT. Verify the CONNECTIONS are made with CLAMP STYLE Marine Posts, Place the ENGINE cable on the lug FIRST, then remaining ones Largest to Smallest, and finish with a Stainless LOCKNUT (do NOT use wing nuts).

CHECK BATTERY CABLE CONNECTIONS ON ENGINE END.

Check GROUND WIRES on ELECTRICAL PLATE for clean and tight connections.

Check the THREE BOLT HOLES that hold electrical plate for clean and tight connections.

Fuel and Oil Levels- Go into Calibration Settings and set both tanks to NOT INSTALLED (you must have a fuel/oil harness and optional remote oil tank sensor to use those features).

[Savage]

Do you have a oil level sensor in the tank in the boat?

[Ogreman51]

I don't think so, Savage. Only sensor (I'm told) is on the mini-reservoir on the head. I did easily find that one, and I replaced it. Only a two-wire cannon plug. The main (on board the boat reservoir) is the kind with two large black screw-on caps. One is the replenishment cap. The other is the more complicated cap with the two hoses (one for the oil pressure from the engine, the other for the oil to be blown up to the mini-reservoir by the oil pressure in the main). I guess there's a pick-up probe on the bottom of the two-hose cap, but it's not a sensor, I believe. It's just a tube which extends to the bottom of the reservoir so as to pick up oil (via the internal air pressure) from the bottom of the main reservoir, first, true??

[Savage]

If there are no wires on the cap, then your gauge is NOT monitoring oil level.

[Ogreman51]

Yeah, there aren't any cap wires on the main oil reservoir, so that makes sense. Since the oil pump is working (verified that by disconnecting the line at the mini-reservoir, and with the engine running at idle, physically saw the oil coming out of the line), I wish there was a simple way to bypass the oil low level warning. Same for the fuel low level warning. Is SC calibration available here to do this and just calibrate out the warnings? I've looked at the SC manual, but it doesn't seem to address doing this. Maybe I'm missing something in the manual? Thanks, Mike

[Nova Kaw 650]

The RPM's dropping when trimming are a dead on indication of low amps/voltage.
Bad connections, bad cables, bad battery or alternator, etc.

[Ogreman51]

Thanks Don and Scott and everyone. I'll be sure to take a look at all you've said, check the battery, and all the connections. WRT the Smartcraft Tach I have, it's a Smart Tow type, designed to monitor more than one engine, I believe, if you need to (I don't . . . only have the one Opti 200). It's also designed to allow one to control the boat from the gauge at tow speeds, but this is an option I don't believe I'll ever use, either. Don, in looking thru the manual, I didn't see a "Tanks Not Installed" option in the calibration section, but I'll look again. Let me know if you have anymore detail on this. Scott, I'll definitely check all the connections. FYI, the SC voltage reading at mid RPM says about 13.7, which sounds like the alternator should be charging ok. But I haven't yet measured the volts at the alternator with a DMM. Need to do this. And check over all the cables. Here's a thought: when I took out the old analog trim gauge in favor of the new "daisy chain" digital gauge from SC, is it possible that one of the old analog wires (which I tried to cover loose ends with electrical tape) might be shorting out on something causing the drop in RPMs? FYI, I also put in digital "daisy chain" oil temp, water temp, and water temp gauges, as well. Perhaps an old analog wire (now un-used) from the old gauges is somehown loose and causing the short? I tried to tape off all the old wires when I hooked up the daisy chain of SC gauges. Just thinking out loud. Please comment back. Thanks for all the help! I really appreciate it! Mike