1997 200hp EFI Mariner bogs on takeoff intermittantly

[Common Cat]

I am having problems with a 1997 200hp EFI Mariner. The problem is intermittant, but on takeoff the motor bogs and will barely get on plane. Sometimes while trying to get on plane or once on plane, it kicks in and runs perfect with full power. Other times it just takes off and runs perfect for several takeoffs. Sometimes it kicks up and back a time or two, before it kicks in for good with full power. I have not been able to pattern it. I have tried to let it warm up longer thinking maybe a temp issue, but that yielded no different results. I have already spent a lot of money with a reputable Mercury dealer in Houston and the problem still exists. I have read multiple forums where many owners experience the same exact problem with this motor, but never post a solution. I finally found one post on here where a new ECU corrected the posters similar problem. Where is the best place to send an ECU for test and possible rebuild? Could the drivers in the ECU cause the power to jump up and down like that? Since its intermittant, would it even show itself on an ECU bench test? I thought replacing both switchboxes fixed it, but it has returned and is getting worse. I really feel its electrical by the way it bogs at take off, but then kicks in and out so fast. Other times it runs perfect with full power. Items replaced are the battery, all fuel lines, both switchboxes, oil valve at VST + all hoses, sparkplugs and both voltage regulators. I also tried shaking the wires thinking it might be a broke wire inside the insulation. Compression is 120 on all cylinders. Mechanic said coils were good. I understand its hard to troubleshoot an intermittent issue. I have tried to live with it, but patience is wearing very thin. Willing to spend the money if I knew a rebuilt ECU would fix it for good. Thanks in advance for your time...

[EuropeanAM]

Some of the more common items found with these complaints (other than your above mentioned replacements) include:

-Cannon plug connector loose/improperly connected
-ECU connector or locking ring loose/damaged/improperly connected
-TRIGGER wiring harness that's internally damaged (becomes intermittent when trigger moves)
-Injector wiring harness problems, or failing/flooding injectors
-ECU injector drivers coming loose from board inside ECU.

You've also got a PM.

[Common Cat]

I have checked the cannon plug and its good. I'll look at the other recommendations and see if I can get this thing figured out. I will definitely post the solution if I can get it fixed. Thanks again for the help.

[usmc7980]

I have checked the cannon plug and its good. I'll look at the other recommendations and see if I can get this thing figured out. I will definitely post the solution if I can get it fixed. Thanks again for the help.

Please post any solutions as I have been battling this for 3 years with a 1996 150 EFI Mariner.

[EuropeanAM]

Please post any solutions as I have been battling this for 3 years with a 1996 150 EFI Mariner.

While it's helpful to know what caused a similar problem on someone else's engine, don't ASSUME that every case of the "same symptoms" will necessarily have the same "cure". That can (unfortunately) be a very costly assumption.

[usmc7980]

I understand what you are saying but I have a 1996 Mariner Magnum EFI 150 that has exactly the same symptoms. I bought the boat in 2006 and deployed in 2007 and it sat for a year. It will bog down and go a quarter of a mile in the hole then takeoff and do 60 mph. It could do this several times today and not do it once the next trip. I have had it to Mercury certified marinas and shade tree mechanics and have spent over $3000. Stator, trigger, power packs (both), fuel lines, filters, and computer all replaced...no change. The owner of our local outdoors shop told me to check out BBC because there was an excellent mechanic who monitored the traffic. I love my Bumblebee boat, hate my Mariner motor. Anything that fixes this would be a Godsend. Thanks.

[EuropeanAM]

I understand what you are saying but I have a 1996 Mariner Magnum EFI 150 that has exactly the same symptoms. I bought the boat in 2006 and deployed in 2007 and it sat for a year. It will bog down and go a quarter of a mile in the hole then takeoff and do 60 mph. It could do this several times today and not do it once the next trip. I have had it to Mercury certified marinas and shade tree mechanics and have spent over $3000. Stator, trigger, power packs (both), fuel lines, filters, and computer all replaced...no change. The owner of our local outdoors shop told me to check out BBC because there was an excellent mechanic who monitored the traffic. I love my Bumblebee boat, hate my Mariner motor. Anything that fixes this would be a Godsend. Thanks.

Would be happy to assist with your specific engine. Open a new thread, and place the above info (plus serial number) in it.

This helps to avoid confusion with the original-poster's engine and problem(s).

[Common Cat]

Ok, update on still existing issue... I sent the ECU to be tested and repaired. They said the drivers were loose which is common in this ECU. They repaired and sent back. I installed the ECU and took it out last Sunday. It ran great first run for about 10 minutes. It seems to have better power overall and I thought all was good. I stopped to fish for 15 min and then cranked up and went to take off and it bogged again. It barely came on plane and was at 4200 RPM's trimmed out wide open. Then after 15 seconds, it took off like a rocket as usual. I ran to next spot and shut down to fish again. After 20 min, I cranked up fast idled out at 1000 RPM's and noticed it trying to jump up and back like it does when I take off. I don't know if that will aid in the troubleshooting but thought I'd mention it. Anyway, after the idle out to safe zone it jumped on plane and ran perfect. So after looking at your earlier post, my question is whats the next most likely cause. I am at $2400 so far... ha I hate shotgun troubleshooting, but at this point, I am out of ideas. Like the other poster, I can't afford another boat and really love mine, if I can just get it running like normal again.

[EuropeanAM]

Some of the more common items found with these complaints (other than your above mentioned replacements) include:

-Cannon plug connector loose/improperly connected
-ECU connector or locking ring loose/damaged/improperly connected
-TRIGGER wiring harness that's internally damaged (becomes intermittent when trigger moves)
-Injector wiring harness problems, or failing/flooding injectors
-ECU injector drivers coming loose from board inside ECU.

You've also got a PM.

Have ALL of the above items (obviously the ECU already done) been checked?

Has the STATOR been inspected VISUALLY for discolored (or burnt) bobbins/windings?

Have the VOLTAGE REGULATORS been inspected VISUALLY for burnt spots, or browned/blackened/burnt connectors (especially on the RED or YELLOW WIRES)?

Plug wires inspected for potential leakage? Good/Clean/Correct Spark plugs (NGK: BU8H)?

I tend to agree that it's likely electrical in nature.... ALL ITEMS mentioned above are electrical possibilities.

[Common Cat]

Possible discolored windings on the Stator. I am trying to post pics for you to review.

[EuropeanAM]

I'd recommend the stator be tested (both OHMS testing AND OUTPUT TESTING WITH A DVA).

Also recommend flywheel be COMPLETELY removed for a better view of the windings (a couple of those look "suspect").

[Wildcat Dude]

some of those windings look like they got really hot

[Common Cat]

I performed an ohms test on the stator and all readings were within specs. Blue 3500, Blue/White 3780, Red 109, and Red/White 109. I'll invest in a DVA adapter and fly wheel puller next and perform the other two tests. Stay tuned... There is definitely some black burn marks on the one set of windings. Not sure if that can cause my intermittent problem, but can't be good either. What color wires will I be checking with the DVA test? I assume it will be from both switchboxes as well. A pain on this motor since they are mounted on top of each other. Thanks again for the help. Serial # 0G529642 I never provided that earlier in this post.

[Wildcat Dude]

You really should invest in a OEM Service Manual from European Marine, it spells it out exactly in it for your motor Course I bet you already heard that

[EuropeanAM]

Definitely obtain the OEM Service Manual... you will need it for OHMS testing and for DVA testing.

I'd recommend you remove the flywheel for VISUAL inspection FIRST. If the stator is VISUALLY damaged, there's no need for any further testing (it should be REPLACED).

[Common Cat]

Ok, Don, I have an update. I replaced the stator and took it out to the lake. It ran great the first two trips, but then at the end of the day on my 3rd trip out, it bogged on takeoff again. I almost couldn't believe it so I took it out two more times after and it has bogged once each trip. Now with that being said, it actually seems a little different now. I'm less inclined to think electrical now because it bogs, but doesn't jump up and down in power as it did before. It usually just bogs and I return to neutral and start over and it works normal the next try. It's possible it might now be fuel related. It doesn't idle smooth and dies occasionally too. The mechanic that originally worked on it disabled the idle stabilizer and hard timed the motor. I will be replacing the impeller soon and will take it back out a few more times to see if I can troubleshoot it further. It is so intermittant that its really hard to figure out. I will say its bogging much less than before so progress has been made. Not happy by any means but definitely not as upset. At least I can fish now. It is 17 yrs old and never had the injectors serviced or new reeds. I do run quikleen and stabil in every tank with super unleaded fuel. But over time, I am curious the state of the injectors. thoughts?

[Wildcat Dude]

well here's my take on that. IF you didn't test ALL the components and you replaced the stator when indeed the regulators were toast too, then you just burned up another stator most likely.

Did you do as suggested and get an OEM Service Manual and test the components - as you didn't say anything in regards to that other than ohms reading on the stator which you said were within specs - BUT windings seem to be a problem.

Yes, fuel related problems can cause bogging too. I think we need to start with the basics and do it systematically. I would definitely think its due to have injectors serviced, as well as closely visually inspect the entire fuel system from beginning to end so you CAN rule it out.

When you say super unleaded, lets talk in octane terms so we'll know if you're following what's specified for that engine and please go through the checklist to rule out fuel problems and get the injectors serviced before you spend money on electrical components that may not have been bad (or are bad) http://www.bbcboards.net/mercury-3-l...tem-first.html

When you say "HARD TIMED" the motor - what exactly does that mean? Never heard the term before.

Can you go through the checklist that Don noted above in his post and tell us what you've done so far on that list? (regarding electrical?)

[ufish2]

Had the same problem. Don't just shake the plug wires, replace them if you hadn't already. Had a plug wire that would allow me to time the engine but was still bad. It only takes one bad plug wires for your engine to run poorly. Cheap fix before you send off a ECU. Did that also and no change. Good luck.

[EuropeanAM]

I don't believe REMOVING the idle stabilizer/advance module has any direct correlation to your problem. Understand that REMOVING it involves physically detaching ALL of it's wires, physically unbolting it, and placing the module at a different physical address (ie- not even in the boat). A complete Sync-n-Link Proceedure (including idle and WOT timing, and idle adjustment IN GEAR, IN THE WATER) must then be completed. TPI adjustment should also be performed (should have been performed when ECU was reinstalled, also).

One question on the "bogging"- does this seem to be occurring most often at the END of your outing to the lake.... after fishing for "X" period of time (engine shut down), etc?

[Common Cat]

Don, that is a good question and one I have not thought about. It does seem to be later on during the day after stopping at several spots to fish. I can't recall it ever bogging on the initial run after launching. I have a milk run of fishing spots so I start the engine and run short distances probably every 10 - 40 min or so. All are very short runs of less than a mile or two max. So, to answer your question, yes I think its after fishing for a few spots. The last trip I was pulling my son and friend on a wake skate and it worked the whole 1.5 hrs while pulling them and then when we wound up the rope and got ready to head in, it bogged. I went to neutral and then tried again and it hesitated a second and then took off. I replaced the ECU so I can tell you 100% that the TPI was not adjusted after the ECU install. I'll check the manual and see if that is something I can do. With regards to the idle stablilizer, he did take it to the lake a couple of times to run it and I am going off what he told me about it being disabled. I actually forgot about it until recently so I'll try and look to see if its physically removed.

Ufish2- I watched the mercury mechanic check for spark on all 6 plug wires, but I have not changed any of them. The wires I mentioned that I shook were the ones going to the switch boxes. That is something to keep in mind to try and I appreciate the input. I would love for it to be that simple.

Wildcat- Yes, I downloaded and printed out the OEM manual. The parts replaced are as follows: Both voltage regulators, Both switch boxes, stator, oil valve at the VST + all hoses, battery and all spark plugs (NGK BUH8). The mechanic tested the coils and said they are good. The ECU was rebuilt and I was told all the drivers were loose. The manual says to run 87 octane if I remember correctly, but local Mercury mechanic told me to run 89 and higher. I do run Quikleen and Stabil in every tank as well. The Cannon plug was checked, the ECU was repaired, the trigger was inspected while the stator was off, and nothing has been done with the injectors or the injector wiring harness. I don't claim to be a great mechanic and probably have not gone about this with the most systematic approach, but I got tired of paying alot of money to so called expert mechanics to keep my boat 6 weeks and give it back the same as I dropped it off. I do appreciate all the help that has been given from this board. I understand the motor is old but think if I can get her right, she has some good years left in her. I need her to last because I cannot afford a new one. Thanks again...