Engine won't get past 1500 rpm

[RickK]

If you can't find one try these guys.  Bought power pack for last motor and the price was great.
http://www.outboardignition.com/mandmse ... l=47&val=9

This is the kind of stuff that we need to add to the resources forum - jdupree, can you post the home URL of the ignition site please. thx
(I could do it but I'd like you guys to start using the Resources section - especially since we all asked for it   )

[bluedolphin]

Just had 3 days of awesome boating - I was off Friday, so I took her out Friday, Saturday and Sunday. However, today (Monday) 4th day in a row, I guess I just had too much of a good thing. The same condition came back - the engine will NOT go past 1500rpm, just like the problem I had before the stator was replaced. Called the mechanic - he will check it out during the week. Should I be p****d off, or be thankful that I got at least 3 days of boating?? What could it be this time??? HELP!!

[GoneFission]

Still sounds like an ignition problem to me...  Maybe they changed the wrong switchbox?   :cry:

If they've done the stator and one switchbox, there's not a lot left to fix, so eventually you will have a new ignition system!

[bluedolphin]

Thanks, GoneFission! I will suggest to my mechanic to look at the switchbox. Hopefully, that's all it is. I will post his findings.

[Ben87]

Man, I do feel for you.  Like I had mentioned earlier, the first time I had this problem, I knew it was the stator by testing it but to be safe, I swapped out the;

1.  Stator
2.  Both Switchboxes
3.  All 6 Ignition Coils

This was pretty much the whole ignition system.  Afterwards, I did not have a single issue in 4-5 years.  

As the motor was an 87 and I did this in 1998, that was 11 years.  At that time, all the parts, new from Mercury were $600 and to me was well worth it to not be stranded.  

I learned that the switchboxes cannot be tested, no one had the ability to do so out of every Mercury place within 100 miles of me so for the money, I swapped them both out.  

I'm at a loss as to what you might do next.  The only thing I can say is to make sure your water pump is good and water is getting into the motor and cooling it, espcially if you boat down south somewhere where both the air and the water are so much warmer than where I am here in MA.  Then there are thermostats and poppet valves and possible clogged passages from no flushing and such, if the motor gets hot, the stator will fry in very short time.  

I hope you do get it sorted out, I remember those days when I had the same issues well.  I lost weeks of boating/fishing time because of it and it is tough to spend the good money and have the problem come up again.

[bluedolphin]

Thanks, ben87. I think you're right on the money. It is frustrating. The mechanic finally had a chance to go out with me yesterday, and would you believe, the boat ran fine. Why is that, it's almost like you go to the doctor and you can't show him what's wrong and he can't find anything wrong with you. But, the engine did stall, twice, and it was hard to start after. Anyway, he adjusted the cards to make it lean, and he says to try that. So I did. I wanted to go out in the afternoon, but the darn motor now won't idle - it kept stalling. I tried it again this morning, same thing. VERY FRUSTRATING!! Anyway, I called the mechanic again, and he said he will come by during the week to look at it. ben 87, it might be time to change the switch boxes and the coils. I will suggest to the mechanic. Thanks again.

[Kaczki]

Excerpt from troubleshooting page in the Old Outboard service manual: "Problem- No acceleration, idle well but when put to full power dies down.
Causes-
A.  High or low speed needle set too lean.
B.  Dirt or packing behind needles and seats.
C.  High speed nozzle obstructed.
D.  Float level too low.
E.  Choke partly closed.
F.  Improper timing and synchronization.
G.  Fuel lines or passages obstructed.
H.  Fuel filter obstructed.  Fuel pump not supplying enough fuel.
I.  Not enough oil in gas.
J.  Breaker points improperly gapped or dirty.
K.  Bent gearcase or exhaust tube."

If I were you I would go through this whole checklist and make sure that everything is up to specs.  This is a really well written manual for all kinds of outboards, not just old ones.

[bluedolphin]

I figured if nothing's working, I might as well get a 2nd opinion. I called another mechanic to look at the problem. He says the one side is not firing, and the switchbox is the culprit. The day he replaced the switchbox, he called me to say he had to leave for an emergency - his daughter was in a car accident - and she's in California. He said everything is hooked up, but he can't run the engine to see if everything is ok. I tried on my own, but I could not even get the engine started. He has not called back since (that's 3 days ago), so he might be in California. Just my luck! Anyway, the first mechanic called me today to say he will change the rest of the ignition components - trigger, the one old switchbox, and ignition coil, around $650 in parts, plus around 2 hrs. labor. Just so I can use the boat (hopefully) this Father's Day, I gave him the go ahead. Keeping my fingers crossed.

[Miguel]

My experience is that older 2 stroke mercurys and mariners have stator/ignition problems.  I used to have a 40HP mercury, which fried 3 stators, and my 1992 Mariner 115HP has gone through one.  The fix is known as the "RED STATOR".  This is supposedly a better version of the former piece of crap.
Just out of curiosity:  Do you hook and unhook the battery often?  Do you use wing nuts on the battery?  I´ve read that it is important to have VERY tight connection at the battery cables.  Replace the wing nuts with good quality nuts and tighten them with a wrench. If not, small arcs can form in the battery connection that will not be well tolerated by your ignition system.
It is very difficult to troubleshoot the ignition system without the proper tools.  Sadly, you may end up replacing every component in order to fix the problem, but you will never know for sure which one was the culprit of your problem.

[GoneFission]

My vote is still that they replaced the wrong switchbox the first time.  The problem you described (1500 RPM at WOT) is consistent with the engine running on 3 cylinders - that's a switchbox for sure.  

Miguel is right on stators - Mercurys before they went to the auto-type alternator did seem to have a problem there.  Mine has had the red stator fix as well.  However, the later Mercurys with the auto-type alternator (big alternator on top of the engine run by a belt off the crank) have largely overcome the stator problem.  

The battery issue is true as well, and applies to all outboards - arcs and loose battery connections will fry the ignition system quickly, as the battery is a controller of sorts for voltage.  Disconnect the battery and the engine will continue to run, but the line voltage goes up to 25 or so volts, arcing will cause even higher voltage that may damage rectifiers and even the beloved coil/stator.

[bluedolphin]

Here we go. First, let me thank everyone for their solid input. Second, today (Monday) a week and 2 weekends with me not able to use the boat, the mechanic came back to hook up all new parts - switch boxes, trigger, coils. Stator was new ( replaced by the same mechanic a month ago), so pretty much the whole ignition system has been replaced. Should work, right? Sad to day, NOPE. He says now that the whole system is dead, like no spark anywhere. And he has no idea why. He wonders if, when I tried to start it with one switch box changed by the other mechanic, there was arcing or spark that may have occured and shorted something. I did not notice anything when I tried to start the engine 1 week ago. He says the best thing would be to take my boat to the shop and use a tool to test each part of the ignition system to see which one is creating the problem. Should I be frustrated, or what? I've spent close to 3k since the problem started and I still can not use the boat. Memorial weekend is past, so is Father's Day. Maybe, by Christmas, I'll be able to use the boat, after spending enough money to buy a new engine. Oh, well, I guess that's what happens when I do not have the ability to diagnose and fix these problems. But right now, I'm close to giving up on boats with outboards. I've had 3 boats before this one, all with twin engines and inboards, and I never had problems like this. All the while, I thought a small boat with an outboard is the simplest and least headaches to go boating. I'm convinced right now that I made the wrong decision to go outboard.

[jdupree]

I am sorry about the problems you are having :cry:   Nothing is more frustrating than troubleshooting and ignition problem.  Since all or most of the ignition components have been replaced, as a last resort I would have someone check for a good ground in the ignition system.  If the motor has good compression, I would not give up on it yet since you have spent the money.  Have you taken it to a Mercury dealer

[bluedolphin]

I'm back!
Well, the good news - the boat is up and running again, at least for the hour that I picked it up from the mechanic's shop, with acces to a dock on the river to my house which is about half to an hour away, depending on speed. The bad news - invoice for $1,500 including 10 hrs labor ($670), and parts - trigger, 2 switch boxes, ignition coil, spark plugs. The stator was replaces earlier for another $600 in parts plus 2 hours labor. After the stator replacement, I ran the boat for 3 straight days (I had vacation days for 4 days) 4 hours per day, and she ran flawlessly. On the 4th day (Memorial Day Monday), the engine exhibited the same problem - will not go past 1500 rpm - as before the stator was replaced. I'm hoping that this last "fix" will have the engine running right for more than 3 days!!!! For crying out loud, all of this is going to a credit card, that I pay off a little bit at a time, and I'm certainly not liking spending/owing more and more on this outboard engine. Like I said earlier, I'm at the end of my patience with outboards, and the next problem will be the end of it - she goes. I'll be looking for twin inboards on a boat, that will likely cost me more, but at least I'm more comfortable maneuvering with twins (single outboard boats, because of light weight, are harder to dock, compounded by stalling problems), plus I never had ignition problems with inboards. And I have had 3 diferrent boats with them before this outboard - from a 26' to a 31'. Anyway, thanks for all the help and suggestions. If you see me post with another problem in the next few weeks, it will be to say good-bye to this boat and good luck to every one with outboards. By the way, the boat is excellent, the engine I can live without.

[bluedolphin]

P.S. Because I like the boat a lot, and it does not use up a lot of gas, I might try an authorized Mercury dealer next time, instead of the mechanic I use now. I spoke with a Mercury technician recently, and he seemed to think along the same lines as the group on this board. Going to a Mercury technician just might mean less hours spent trouble shooting, because he will know what to look for - less trial and error, I hope. He actually told me that ignition coils do not "usually" wear out, so he questions the mechanic replacing mine. Does anyone know of a Mercury shop in Ft. Lauderdale, Fl.? In the meantime, I will try and google. Thanks.

[JimCt]

Solve the problem for good and get an inboard.