Good Day to be on the Lake, bad day on the lake...

[ronb]

Today's weather was perfect, low 70's 60°f water temps, sun shining, slight breeze, a few of my wife's coworkers, great day to be on the water!

But the 'toon (rather the Mercury 90 Optimax) disagreed. It idled a little rough, it ran fine, until I asked it to 'go fast', when I did that, it fell right on its face and died. Once the motor was stopped I could fire it right back up again. A couple times I was able to bring the throttle back to near idle and keep it running and then speed back up, but then it would die again.

I docked and pulled the motor covers off looking for anything obvious (broken wires, leaking fluids, loose spark plug wires) no luck. I put the covers back on because our guests had arrived and we headed out at low speeds (under 3k). When our next friends arrived we were going to cross the lake to a sand bar, them in their speed boat (88hp 2cycle Evinrude) and us on the 'toon. The maximum RPM that it would let me run without cutting out/dying was 3800, trying to push up to 4k would only result in the engine dying.. not great, nor reassuring to my wife. We haven't even made a payment on this 'toon yet...

Well we cruised at 3800 dropping down to 3600 (with no change in location of the throttle) and eventually made it over to the sand bar. Last time I had this toon out, I was running a 14 x 13p prop and it was WOT at 5800 (20mph) I really wanted to test out the new 13.73 x 15p to see where it left the WOT RPM and what top speed we could hit. That never happened and I think the prop had nothing to do with my issues, just that it made the day a little less enjoyable.

On the way back from the sand bar it did not cut out, but with the throttle all the way forward I could not exceed 3200RPM.

The first time this happened I was out with my Mom and Step-Dad, I was doing some slalom type turing on the lake, back and forth, back and forth and then it died. It started right back up again and never had another issue. That was last Friday (5/22/2012) which would have only been the 4th time that I have driven this boar (1 test drive, 2 nights out with my family, 1 night out with my Mom/step-Dad).

My guess is that I have a piece of 'foreign material' floating around somewhere restricting fuel flow and sometimes blocking it completely.

When we bought it, the gas tank was completely empty so I know that the salesman filled it up with gas from a regular gas station (no resort gas) and after I bought it, I topped off the rest of the tank at a gas station that I frequent for my own cars/truck/lawnmowers/tractor.

I found plenty of other articles on this topic for the same size/model motor as well as other sizes in the same Mercury motor family..

OptiMax 1.5L 75 - 125 HP
http://www.mercurymarine.com/engines/ou ... L/?model=1

I obviously have some reading to do.. I had no idea about this until I was talking to this guy that looked like Grizzly Adams today when we were parked on the sandbar..

The OptiMax Air Compressor provides a steady charge of cooled air for maximum combustion efficiency.

2008 Mercury Optimax EFI 115 Problems at low RPMs
http://forums.iboats.com/showthread.php?t=492952

2001 Mercury OptiMax 150-HP Cuts Out
http://continuouswave.com/ubb/Forum3/HTML/013015.html

This sounds almost exactly like what I am experiencing!
2008 Mercury Optimax 90 - loss of power
http://www.ohiogamefishing.com/communit ... 33482.html

11-16-2009, 08:27 AM
My 2008 Mercury Optimax 90 won't go above 3000 rpms and stalls occasionally at idle. Any idea what's wrong? Here's some details below.

After running the Merc for a few miles yesterday on Lake Erie (perch limits!)without any problem at full throttle, I anchored to perch fish for 4 or hours. I started the motor up again and could not get it above 3000 rpm's and it vibrated a little like it was struggling. Returning to the launch slowly and unable to go above 3000, it stalled several times at idle in the no wake zone.

I checked the prop and it spins freely. I've had no prior problems with the motor. I plan to check the plugs and pull the engine fuel filter to see if there is any debris in the gas. I've been to Canada twice this year and filled up at remote places. I keep the gas treated with Stabil at all times plus the recommended treatment for Optimax (quick clean or something like that). I'm suspecting bad gas (water) or something depleting the gas supply.

How can you check if there is water in the gas? I'd like to rule out fuel problem; otherwise it's warranty work.

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He answered his own post with the solution.

My hats off to the guys at Vic's. I dropped the boat off saturday and they had my optimax fixed by tuesday. Nice people to work with!

It turned out to be one bad coil/switch combo Apparently, Mercury was supplied with lots of bad coils in the last few years. The good news is that there is one coil and switch for each cylinder, so if one goes bad, you can at least run back to the launch. Older Merc's have only one, so you would SOL, so I'm told.

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hrmm, being in ND with our 'Blue Laws' means that nothing is open until noon tomorrow, but then again Moorhead MN is only 3 miles away...

so in the morning..
check filters (air/fuel)
check plugs (color)
check electrical connections

call around to see if there is anybody who can hook this thing up to a ocmputer to read the diagnostics...

-ron

[oldcoot]

I think you're right about a dirt ball in the fuel filter OR also check for any critter nests in the tank vents if there are any....found out the hard way on another boat I had after a wasp nest got into the vent....

[ronb]

I think I found one of the main problems..

IMG-20120603-01233 (Custom).jpg (38.07 KiB) Viewed 6981 times

This moto is a 3 cylinder and the top most spark plug looks like it hasn't fired in forever. I will throw a new set of plugs in it The originals (when I bought it) were

ngk
IZFR5J

which nobody in town has, but they do have
autolite $6
xp5224

I'd like to find the test procedures (ohm readings) to test the coils. The number 1 coil has a different part number than the other 2.
879984T00 REV-A

whereas the other two have part numer..
879984

The air filter looked a tad diry, the fuel filter looked fine. One problem I have now is what to do with 28 gallons of gas that is in the tank, its going to be hard to see anything in there, and I don't have enough gas cans to drain it all out.

[lakebilly]

I think I would rule out fuel for now. At least until you get to the bottom of the fouled / defective plug. The engine seems to be running fine on two out of three cyclinders. Incidently, if WOT is around 5800 RPM it would seem to reason that with one plug not firing 3800 RPM would be all you would get.

You might try a spark gap tester to test that #1 coil. They are available at places like AutoZone for less than $10.00. They plug into the spark plug wire just like a plug would. They also have a ground wire with an alligator clip that has to connect to a ground point. Once connected, you crank the engine and look for a spark.

I've seen it many times where the coil is fine and the plug itself is bad, even brand new ones. Either way, the spark gap tester should tell what the culprit is.

Once last point. Mercury recommends running QuickKeen to help decarb an engine that has been misfiring. So, once you get it back to full RPM, give it a good dose of QuickKleen.

Also, one other important question. How many carbs on this engine?

http://www.autozone.com/autozone/access ... 10257_0_0_

http://www.amazon.com/Mercury-Marine-Qu ... B003ZF1GJQ

[ronb]

I have a spark tester somewhere... If I don't find it tonight I will buy another tomorrow. The new spark plug nade no difference. This engine is EFI- no carbs.

-ron

[lakebilly]

Most likely it's your coil. They are prone to failure. Once you find a spark gap tester, you'll know in short order. To know for sure, you'll have to swap the suspect coil with one of the known good coils. If the problem moves with the coil, it's a bad coil. Otherwise, you'll have to keep looking. My $dollars are on a bad coil.


Here's a replacement coil price for reference:

http://www.perfprotech.com/store/Catalo ... rch=879984

[ronb]

I found a pdf online talking about PCM failures and it had buried in it the procedure for testing the coils using a ohm meter
http://www.marinemechanic.com/merc/dist ... ilures.PDF

coil.jpg (77.51 KiB) Viewed 6682 times

testChart.jpg (148.05 KiB) Viewed 6683 times

testChartNotes.jpg (88 KiB) Viewed 6681 times

I don't have the test harness that they refer to, but based on my preliminary attempts to read the resistance, I suck and getting the tips of needles to touch. My tester has sharp round points on it and the terminal ends on the coil are sharp round points tucked up almost 1/2" inside the housing (so you can't easily touch their sides or the wide flat parts)

I will get some readings and a spark tester later..

thanks for the link to the reference prices, seems to be on par with what I've found so far..
http://www.ebay.com/sch/i.html?_from=R4 ... nkw=879984

and I did look at other sites too..

Since I have had this boat for exactly 1 month today and have only been able to enjoy it 3 times on the lake trouble free, do you think it is out of line to ask the salesman to cover the cost of this? He said they had the motor 'checked out' before we signed the papers, and that he would not leave us 'high and dry'.

-ron

[bruuuuce]

I found a pdf online talking about PCM failures and it had buried in it the procedure for testing the coils using a ohm meter
http://www.marinemechanic.com/merc/dist ... ilures.PDF

coil.jpg

testChart.jpg

testChartNotes.jpg

I don't have the test harness that they refer to, but based on my preliminary attempts to read the resistance, I suck and getting the tips of needles to touch. My tester has sharp round points on it and the terminal ends on the coil are sharp round points tucked up almost 1/2" inside the housing (so you can't easily touch their sides or the wide flat parts)

I will get some readings and a spark tester later..

thanks for the link to the reference prices, seems to be on par with what I've found so far..
http://www.ebay.com/sch/i.html?_from=R4 ... nkw=879984

and I did look at other sites too..

Since I have had this boat for exactly 1 month today and have only been able to enjoy it 3 times on the lake trouble free, do you think it is out of line to ask the salesman to cover the cost of this? He said they had the motor 'checked out' before we signed the papers, and that he would not leave us 'high and dry'.

-ron

You are on the right track with the coil pack, same symptoms as mine last year. Mercury had a bad bunch of coil packs go out, according to the Mercury Dealer I went to. Contact a Mercury dealer near you, might just cover it under warranty, even if it is out already.

It is a quick easy swap and you will be back up and running on on cylinders quick.

[bruuuuce]

If you want to test it here is how you can do it. Hook it to a garden hose and let it run, take a pair of pliers and start unhooking spark plug wires one at a time (don't get bit). If you unplug it and it doesn't die or start running rough then that coil pack is bad. If you unplug it and it runs rough or dies that coil pack is good.

Change the coil pack from the cylinder it is on to another and repeat the test and you should see the symptom go with that coil pack.

I was going to buy one for around $110, they were hard to find last year. I found a Dealer in SE Missouri who had one and he was the one who told me about the issue of the bad packs, told me if I brought my boat in and let him fix it he could have it done under warranty, so I pulled the boat to him. He hooked it to his mercury laptop, read the serial number, did a test with it and it told him which one to replace. He replaced it, retested it and submitted the claim to Mercury and sent me on my way. I was there 20 minutes tops. I fused with it in my drive way for 3 evenings and one entire Saturday troubleshooting it myself

[ronb]

Maybe I am just too cheap to haul it to anybody for something as simple as a coil change.. but one of the Marine parts places (J&K Marine in Detroit Lakes, MN) muttered something about the possibility that it was under warranty, the motor is a 2006 90ELPTO (on a 2007 toon) and according to another technician the original motor only had a 3yr warranty.

So far I have found two in stock locally, one for $168 and one for $138.

Is there any difinitive way to know if it is under warranty before bringing it in?

FWIW, I had been a ASE mechanic for 7 years certified in Brakes, Electrical, and Suspension so I'm no stranger to diagnostics or repair, I just don't know where to find boat specific information (warranty/recall/repair guides).

Another way of testing a coil that does not require you to get electricuted is to use a standard test light.

Clip the ground clip to a good ground location, and then pierce the spark plug boot (at either end) the light will ground the wire and by holding on to the plastic on the test light you will not get electricuted (as I have had happen a few times when using pliers) I also have the 'special' spark plug wire pulling pliers that are insulated at both ends, but after so many years I've gotten leary of the shocks...

I bought a spark tester last night but didn't get around to using it, the dealership where I bought the 'toon from said he would buy the new coil. So I am going to let him and then resume trouble shooting after the coil has been replaced.

-ron

[ronb]

Well now I just feel like an idiot..new coil in, good spark, no compression on #1 cylinder. My gauge may be wrong, it measured 0 on 1. 45 on 2, 30 on 3. Tested both dry and wet with about 1/2oz oil.

Why on Earth didn't I have that tested before signing on 5/4?

Frick me
-ron

[ronb]

I dropped it off with Crystal Pierz this morning. They just confirmed no compression on #1

#2 and #3 were between 115-120 (normal)

But I got another kick in the teeth... The onboard ECM refuses to communicate with the diagnostic computer, freaking awesome!

He said a reman (Mercury) powerhead and 29. Will be about $4400 on parts alone (no labo estimate until he gets the ECM info)

Arg!
-ron

[GregF]

Big Ed will sell you a new 125 HP optimax for $8400

http://www.edsmarinesuperstore.com/mercury.htm

[ronb]

The toon is rated for 115hp max, and at some point as much as I like this toon, when is it "too much" and when do I start considering things like returning it to the dealership. I don't make the first loan payment until next week. We didn't dicker about the price ar haggle about anything when buying this boat. We specifically stated our concerns to the salesman about being new to boating and worried about something like this and he assured us of 2 things.

1. The motor wasa 'checked out'
2. He would not leave us 'high and dry'

I am startin to question both of those statements.

I have started Yard Tooning... Its not as nice as tooning on the water but it takes much less gas and travel time and I always have access to running (drinkable) water, a bathroom, and beds for the kids when they get tired.

YardTooning.jpg (11.37 KiB) Viewed 6199 times

-ron

[badmoonrising]

at some point as much as I like this toon, when is it "too much" and when do I start considering things like returning it to the dealership. I don't make the first loan payment until next week. We didn't dicker about the price ar haggle about anything when buying this boat. We specifically stated our concerns to the salesman about being new to boating and worried about something like this and he assured us of 2 things.

1. The motor wasa 'checked out'
2. He would not leave us 'high and dry'

I am startin to question both of those statements.

Have you called them ? If this were me, I'd call the bank and state you will not pay until this is fixed by the dealer. I would have already towed it back there and refuse to leave until they agree to fix it.