Outboard Problem

If a foreign object is big enough to get through the pickup strainer and cause a blockage there is something wrong with the strainer .

When and if the foreign object-is found see if it fits through the strainer on the leg then if not how did it get inside and cause a blockage ???

Growing up, my uncle was Mercury and my father was Evinrude and neither one ever had trouble. Now, on the lake we were on, the mineral content caused the same issues as salt water and the prevailing attitude was not to get Mercury or Mercruiser for salt water, but fine for fresh.

However, the only real issue with Mercruiser was removing the lower unit as the required tool was always a crowbar and you risked breaking the case. There were strong arguments between the brands, but honestly I could tell performance issues and not really quality there. Still, my cousin lived on the coast and Mercury was frowned on there.

I notice in South Florida a lot of Mercury. First, a lot if you just count Whalers. But other center consoles use them too. We have Yamaha on our center console. I don't know a lot of Evinrude owners but I know some who are very happy with them. I don't see enough of any other brand to even pay attention here. Most outboards here are on center console.

Oh, do see some Seven Marine for people who need more hp, twin, triple and quad 557's. Triples on a 42' Invincible were clocked at 81.6 mph. They introduced a 627 but I don't think have built any. Since fuel economy is important, they have a chart showing that at 65 mph on an Intrepid 370, they get better fuel mileage than either Yamaha 350's or Mercury 300's.

The Mercury dealer on the lake had a far better reputation than the one the OP is dealing with.

I don't recollect seeing anywhere on this thread exactly what this warning tone was supposed to warn of..? Surely the manual would advise what it meant, thus narrowing down the likely causes. However, I also agree that nothing that could get sucked in should be big enough to block anything. I am totally unconvinced that removing the powerhead has even been indicated as necessary yet, but if so, 6 hours is ridiculous, as others have intimated. This outfit is just plain dodgy. I bet it's just a faulty warning device. Did they try changing that..?

I think the OP's motor (25 Merc 4s) is actually a rebranded Tohatsu. Tohatsu's seem to have a pretty good rep in saltwater, and that thing is WAY too young to have serious corrosion issues.

This brand thing is nuts. 99% subjective.
Just because you see lots of engines of a certian brand (like Cummins or Yamaha) does not mean they are the best. In some areas there's only one dealer and it's obvious what brand you'll see on boats in that vicinity. I don't know of any bad major brand engines.

Sounds to me like the subject engine on this thread is not the problem. Probably the dealer. Bur we here on the internet do not have all the information. If we did we then could make good judgement.

In the old days Mercury was a high end engine w quality parts and design features like roller bearings and one pice head/cylinder castings that the other brands lacked. And you rarely saw a racing engine that was not Mercury. But that did'nt mean it was the best engine. The one piece powerhead was good for running and dependability but not so good for servicing.
And for durability if used properly you can't beat the record by some of the sawmills in this PNW area of the Mercury Mk58 50hp inline four cyl. engine's performance in the log ponds. Kinda like a tug but little boats pushed logs only. They operated the throttle like a hand pump and used full throttle most of the time. Many of these engines were used for well over a decade in such service. They rebuilt them at times but probably not completely. Never saw a Johnsonrude or an Evinson on a boom boat, bull boat (or whatever they were called). Great engines.

But that was 50 years ago. However the English have been drinking tea for a long time.

Mercury was always the leader in racing engines but that has absolutely nothing to do with their issues or non-issues in salt water on regular boats. Brand is a factor, but we don't know how much. For those who have a choice, Yamaha is preferred more than Mercury.

I do agree though that in this case and many, the dealer is more in question than the brand, in my mind. I'm hoping he can talk to someone else there on site with more experience and knowledge and more appropriate plans, a more senior mechanic or a manager. If not, then involving Mercury seems like the answer. The mechanic has had two shots and just letting him go as he wishes, I greatly fear three strikes and disaster. Nothing shows knowledge and experience. The fact the OP left with the boat and same problem as he had when he took it in speaks for itself.

Also, while the level of issues vary from dealership to dealership, Marine Max does not have a good reputation for service in Florida (or most other locations, but FL is on topic here). That reputation has been earned and not just on Mercury outboards. Now, Marine Max Stuart actually has some good reviews online too. Main criticism I see is not returning phone calls. In general, I've just known many less than happy Marine Max customers. The least happy have been Azimut buyers. Second has been Whaler and Mercury buyers with little issues not being fixed and same problem again. Third has been purchasers of Sea Ray L Series during the first two years of production.

BandB,
People usually buy what they see most of assuming it's the best. Kinda like anchors.
One can only criticize that to a certian extent though. I bought anti-fowling paint in Alaska that way. There was a huge stack of brand Y in the store and don't remember seeing anything else. I bought brand Y. There was more to it though.

What does OB racing have to do w salt water? Are you saying most racing takes place on fresh water? Never thought of that but it could be. Most of our water around here is salt and of course there's racing on both.

Some people say that good racing performance dos'nt indicate a good cruising engine and IMO there's an ounce of truth in that ... an ounce.

Nomad Willy said:

BandB,
People usually buy what they see most of assuming it's the best. Kinda like anchors.
One can only criticize that to a certian extent though. I bought anti-fowling paint in Alaska that way. There was a huge stack of brand Y in the store and don't remember seeing anything else. I bought brand Y. There was more to it though.

What does OB racing have to do w salt water? Are you saying most racing takes place on fresh water? Never thought of that but it could be. Most of our water around here is salt and of course there's racing on both.

Some people say that good racing performance dos'nt indicate a good cruising engine and IMO there's an ounce of truth in that ... an ounce.

Click to expand...

What I was saying was that there is no correlation between good racing engines and good production engines. Totally different worlds.

I think you underestimate the buyer. I think buyers do gather information. It may not be scientific, but most buyers talk to others and look at online comments and reviews.

Then there are some boat builders who limit you. Certainly makes sense for Brunswick to only allow Brunswick engines. Then some competitors will only allow other brands. And not to forget that Yamaha does own some boat companies and has owned others.

My personal view is that I had the choice of Yamaha 300's or Mercury 300's and chose Yamaha. However, if I wanted a Boston Whaler it would not bother me at all that they came with Mercury. In terms of good, they're both good and if one is better it's just by a small bit.

Is there an update ???

My newest Mercury was a 1988, 200 HP. The one I still have is a 1986, 6 HP. Had great luck with the 200s on my charter boats, but that was almost 30 years ago. Back then John-rudes (Johnson & Evinrudes) didn't hold up in the saltwater charter business, but that was almost 30 years ago. Now a days, Yamaha seem to own the saltwater charter business (in the mid Atlantic). Swore I would never own another OB over 25 HP, but I'll probably eat those words.

Ted

I had a failed Merc on my dinghy, so naturally I went to the Merc store for replacement. I wanted to take advantage of needing to replace the outboard, to move up a little in hp. After a thorough discussion of my needs and wants, the Merc dealer sent me to his competitor at the Yamaha store, as he didn't think I would be happy with the Merc product. I was after more hp AND less weight, as the dinghy had to hang on my davits.

Yamaha delivered.

I subsequently moved to a different dinghy, that had a Honda on it. Now, the other manufacturers have caught up in their development of 4 cycle outboards, but 7 yrs ago, Honda was already a proven reliable product. So far, I have had to pull the bottom end and deal with the water pump once and last year I put in a set of spark plugs.
This year I need to put on a new prop, as the scars are adding up on the old one.

When I was looking for that new (used) dinghy, I had in mind that when in Mexico and Costa Rica on vacations, I rarely saw an outboard being used by the locals that was other than Yamaha. The most common being up to 70 hp with pull start.

Update:
Dealer removed lower unit--no blockage or restrictions
Bore scoped up to power head and no restrictions
Tomorrow they will flush for several hours with descaling solution at idle speed.

Then what??

Stuart has some of the worst water I know of. I need to clean the strainers every two weeks while there. However if the pee stream is good I don't think that is your problem. I would suspect a faulty thermostat.

hmason said:

Update:
Dealer removed lower unit--no blockage or restrictions
Bore scoped up to power head and no restrictions
Tomorrow they will flush for several hours with descaling solution at idle speed.

Then what??

Click to expand...

Howard, as I posted earlier, have they tried swapping out the warning device..? To me it sounds likely that it is the faulty item, as everything else appears to pass muster. I find it hard to believe that water jacket build-up would cause enough overheating to set off an alarm, unless the alarm itself is faulty.

As an aside, but to demonstrate that statement, I had the engine in my car damaged once by an outfit who had moved out of their area of expertise and into car servicing, (they should have stuck to brakes), and I was silly enough to allow them to do what should have been a simple grease filter and oil-change. Without my permission, (and trying to impress I guess), they put a coolant flushing cleaner into the radiator, told me to run the car two weeks then bring it in for a flush. They did not do the required pressure & reverse flush (I found out later), just pulled off the bottom hose then ran a water hose in at the top for a few minutes. Two weeks later the the engine overheated on the freeway, cracking the head in the process, and the radiator when pulled was absolutely clogged with water jacket scale that had been causing absolutely no heating issues left alone, but once dissolved into a sludge, just blocked the radiator core solid.

thermostat was replaced

hmason said:

Update:
Dealer removed lower unit--no blockage or restrictions
Bore scoped up to power head and no restrictions
Tomorrow they will flush for several hours with descaling solution at idle speed.

Then what??

Click to expand...

So, they still have no idea what is going on? Well, at least they're doing something.

a little googling lead me to.....

"If you are overheating, and you have already done the pump and tstat, then it's going to a bad head gasket. On these the head gaskets and exhaust cover gaskets are 1 in the same. And what would be going on is exhaust gasses are getting into the cooling water side of things, displacing water"

source:
2007 Mercury 25 HP efi 4 stroke warning lite and chime. Starts

I assumed the tech performed an IR temp gun test to see if the temp matched the designated alarm temp, but....

hmason said:

Update:

Tomorrow they will flush for several hours with descaling solution at idle speed.

Then what??

Click to expand...

Did that solve it ??

My bet is this: Thermostat seized. First tech goobered new tstat install. Second tech will figure that out. Eventually.

Or it was a faulty thermostat from the factory. I found two once and I proved it by putting it in boiling water and none opened.

....enquiring minds, want to know....

6 hours of flushing with a decalcifier and very little water comes out. Waiting for next step.

hmason said:

6 hours of flushing with a decalcifier and very little water comes out. Waiting for next step.

Click to expand...

Obviously then after all these days they don't know the problem. Have you found anyone there you're convinced knows what they are doing?

I have had a few OB's where the copper pipe coming up from the water pump entered a rubber grommet at the top end. Grommet was swollen from some sort of chemical action. Choked off flow. Took powerhead off and trimmed the offending material. That fixed it.

Later I got a little smarter and made some tools that could trim it through the tube from the bottom end. Laporoscopic techniques are cool!!!

But those were 20yr old machines. This thing is new in comparison.

My opinion only, but I would get in touch with Mercury and let them deal with the problem.

Ski in NC said:

I have had a few OB's where the copper pipe coming up from the water pump entered a rubber grommet at the top end. Grommet was swollen from some sort of chemical action. Choked off flow. Took powerhead off and trimmed the offending material. That fixed it.

Later I got a little smarter and made some tools that could trim it through the tube from the bottom end. Laporoscopic techniques are cool!!!

But those were 20yr old machines. This thing is new in comparison.

Click to expand...

Pipe's collapse with temperature variations too.

any new developments ??

It's to be ready by Monday. It ain't going to be pretty. They claim it's not a warranty claim. I will pay to get it back as we need to leave FL to head north. I plan to deal with Mercury as I can't wait any longer. It's my fault it is filled with salt as I didn't flush it after every use. More to come. I'm not done with this.

Lots of outboards live in salt water on the back of runabouts, I`d be amazed if some ever get flushed, ever or rarely, yet no reported epidemic of salt blocked cooling passages. If most motors are ok with it, why not this one? Something is wrong. Design issue? Done any searching for other owner experiences?