posted 07-17-2005 04:39 PM ET (US)        

After 3 months (!) in the shop, the still under warranty engine was returned to me with a "don't really know what's wrong, but we got'er running". After calling Mercury Marine to try to better understand what was wrong, they told me that the mechanic had 'changed out everything", including a computer module, several jets, fuel pump and a few other miscellaneous items. The boat ran well enough to get home, and I enjoyed what was left of last year's summer.

Fast forward to this year..same symptoms appeared, same rough idle and coughing. Yes, I consistently renew the fuel and run the engine to make sure nothing gets 'stale". I called for (yet) another service appointment (3rd in less than 12 total engine hours). Two months later I towed the boat in and trailered over to the Boston Whaler dealer. After a week and a half, I got the boat back...they insisted that some fuel had gone bad and gummed up the carbs. Two rebuilt carbs later I had the boat back in the water. Next day I took her out for a high-speed run....boat was up to about 20 knots, back down to 10K for a few moments, then...the engine dies within about 50 feet of the rocky breakwater, LOTS of large rocks. The last thing I remember hearing before she died was the sounded like the fuel pump "clicking" as the engine wound down. of course, the engine would not restart..had to phone a friend to come tow me in while paddling furiously to keep off the rocks. Needless to say I was disappointed in the quality of the repair..obviously, my engine was not repaired.

After tieing up at my dock, I tried to restart once again, just to make sure. Engine started, idled roughly, spit and coughed (sounding familiar?), and died. Just like the other 3 times!

Frankly I have had about enough of this...a brand new Mercury engine with less than 13 hours should not behave this way. I am interested in hearing from others who have had similar experiences...I know there are many out there because the service manager at the Boston Whaler dealer told me "we've seen a lot of problems with this (90HP four-stroke) engine". I have researched this forum as well and have found numerous accounts of trips and summers ruined from these kind of apparent fuel-related issues.

What is being done by Boston Whaler/Mercury to satisfy customers? I am tiring of being told things like "it's bad gas" and "you need to run it more" and other blame-the-user excuses. My two neighbors have 17 Montauks, one with a 2-stroke Johnson 90 and one with a Yamaha -- both start instantly and run flawlessly after sitting sometimes for an entire season. No extra "additives" or precision fuel handling tactics are needed for their families to enjoy these boats.

This is obviously a flawed fuel system design for this motor, and Mercury Marine ought to be accountable for the wasted time, energy, and expense (not to mention possible serious injury) this has caused.

posted 07-18-2005 09:36 AM ET (US)            

In your previous article you mention that you keep the boat stored with the engine tilted fully up. I wonder if this is affecting the problem. Perhaps the carburetors don't like sitting in that position for long periods of time.

Also, I think you are in California, and perhaps the local gasoline has been formulated in such a way that there are significant problems in storage.

I know it is frustrating, but if all the mechanics keep telling you that the problem is bad fuel, perhaps that really is the problem.

Since your boat is a MONTAUK (I believe), you probably have on-deck fuel tanks. Have you tried a different fuel tank? I'd change everything I could in the fuel system to see if the problem can be isolated.

posted 07-18-2005 12:39 PM ET (US)            

A mechanic that services the Mercs for the Navy on Coronado Island told me that if the boat isn't run every week or so that it's a good idea to drain the bowls on the carbs. He also recommended a fuel stabilizer. He mentioned that in his experience (and he has quite a bit) the 90 Merc has been a good reliable motor.

I appreciate your frustration though-in my case I just winched it back up the trailer and went home to sort it out. Drifting near a jetty is another matter.

posted 07-22-2005 07:38 PM ET (US)            

I am going to take a trip over to the dealer tomorrow to verify the fix, and then, hopefully, take the boat home. I'll let you all know if this is truly "the" fix. Bottom line is that I wanted to let everyone know that it wasn't a "bad gas" issue..sometimes things do fail mechanically and mimic some obvious user-correctable behaviors. I appreciate the dealer being honest with me and taking the initiative to find the root cause of the problem.

posted 07-23-2005 03:13 PM ET (US)            

quote:

---

Darn Yamaha powerheads - they just don't make them like they used to. Try taking it to a Yamaha dealership for service, since that's what it really is, and quit blaming Mercury.

---

This is total BS. It's a Mercury product....period. Mercury should face the music and take it back or fix it correctly. If I sold a product with other manufacturers parts on them, I am still responsible for the whole product's performance.

General Motors, Ford, BMW, Daimler-Chrysler, etc. all make automobiles but they sub out almost all of the pieces to companies such as Bosch, Johnson Controls, Siemens and so on. Do we as consumers blame Bosch for bad fuel control systems? No, we have GM replace the part or fix it.

posted 07-24-2005 02:34 PM ET (US)            

To me this is just plain bad design, out of touch with how real people use their products, and with unealistic expectations for most of the readily-available fuels. A Boston Whaler is not a lab experiment, it is or should be (for the most part) a turn-key family appliance. Treat it well, keep it clean, follow the instructions, and it should start and run consistently well, without the need to perform fuel analysis, pressure testing, constant carb maintenance, etc.

Naturally I asked the dealer for recomendations for how to keep this engine running...he told me to use their "Mercury Fuel System Cleaner" with every new tank. I asked about "running the engine dry" after use...he said that "you really can't do this with this 4-stroke design", so don't bother.

When I asked about additional filtering and water separation, he said "not necessary in my opinion." Nevertheless, I am inclined to put this additional filter inline to add another measure of filtration in the hope I can avoid this mess in the future.

posted 07-24-2005 06:57 PM ET (US)            

Assuming you keep your under the cowel in-line fuel filter clean (do you?) the particulates from the fuel will not enter the engine. Did you use a fuel stablizer at the end of LAST season so fuel did not sit in the carbs over this past winter? You may have run the fuel out but did you drain the bowels? It sounds like you don't (or didn't) use the engine much if you're only puting 12 hours on her in a whole year.

I'll agree the carb lever falling off is no good but it sounds like that might have been done by your DEALER since you say THEY rebuilt your carbs. Sticking purely weith the fuel issue, I don't believe your dealer's assessment that this is just the way the carbs on this motor are.

My dad used to always say there were two types of people:
1. Those who will have a problem with whatever brand of equipment they buy becuase they don't do the little things to maintain it properly.
2. Those who have next to no problems with equipment (regardless of what brand they buy) because they pay attention to the little things and maintain it properly.

I'm not passing judgement or saying you are either type of person just stating a general fact that I believe based on what I have experienced over the years with cars, boats, weed eaters, generators, lawn mowers, chain saws, and motorcycles.

posted 07-25-2005 01:51 PM ET (US)            

As for the powerhead, it is all Japanese content. I read somewhere (sorry for the vague citation) that Yamaha makes so many of these that they have a separate production line for the Mercury version--there is enough difference from the Yamaha model that they can't be built on the same line.

I agree with drewc, the engine should run in real-world circumstances. If the engine sits for a couple of weeks, you shouldn't have to overhaul the carburetors.

posted 07-26-2005 04:49 PM ET (US)         

If you remember, during the dumping investigations, Yamaha made a big deal out the fact that Mercury was so inept in bringing 4-strokes to market on a timely basis, that they had to buy COMPLETE engines from Yamaha for this 75-115 segment.

posted 07-27-2005 03:06 PM ET (US)            

The carbs are Keihin branded, and do feature an abundance of very tiny passages that were clogged with gummy fuel residue. Rebuilding was simple enough, and all of the gaskets were reusable in my case, which is good because Merc wants $110 per carb (x4) for the rebuild kits.

The biggest obstacle I faced in the rebuilding process was agonizing over the choice of which carb synchronizing tool to purchase. I hate the mercury-tube-style synchronizers, and wanted to purchase a solid state tool, and ended up with the $700 (ouch!) VacuumMate, which works very well.

I was told by my Whaler dealer (the Outboard Motor Shop) that the engine powerheads are supplied by Yamaha, but only the top-end is actually a Yamaha design. The guy I spoke with claimed that Mercury designed the bottom-end (crankshaft & such) to mate with their lower units. I gathered that Yamaha is assembling their top-end onto Merc designed (and Merc-supplied? dunno) bottom-ends and shipping the powerhead assembly to Merc for final motor assembly. I don't have any actual confirmation of the details of this process, however. The mix of metric and SAE fasteners I encountered seems to lend support to this notion.

I sure wish I had been able to purchase the 115hp EFI engine instead of the 90hp carb engine. I really don't like carbs, but I didn't want to undertake the repower myself (and the dealer said they wouldn't do the repower). I'm still considering it, although I doubt I'll actually spend the money until this motor starts giving me much more serious trouble (i.e. the wife becomes worried enough for my safety to support the expenditure :-)

posted 07-28-2005 12:39 AM ET (US)            

I believe that they are manufacturing these carbs in Asia, not the US. Keihin and Mikuni are the two carb vendors of choice for all of the Japanese motorcyle and outboard manufacturers, as far as I know. It looks like Keihin makes their carbs in Japan, China, and Taiwan, with a new facility in Brazil under construction.

posted 07-28-2005 06:34 AM ET (US)            

You don't really need to put quickleen into the tank every single time, but its a habbit and I am not having problems.

If you use your boat every week, then you won't have carb problems, but alot of us don't. So its a good idea to put some quickleen.

Went to outboard motor shop (dealer) and noticed on there NEW montauk 170 that it had a fuel injected 90 hp 4 stroke Merc.

posted 07-28-2005 10:09 PM ET (US)            

We go round and round about who makes the engine, what brand of carbs are on there, and where the carbs are made.
All this going back and forth on carbs is oblique to the central issue at hand. Where Keihin carbs are made does not make a ratt's butt. They are fine carbs and have a proven track record. As BillS correctly points out, they have been on Harleys for years now and have overall been superlative. They are not known as "performance" carbs but are fuel efficient and extremely reliable. In a pinch, they can be easily modified to give you a good bit more power - I know, I have personally drilled and re-jetted several of them.

posted 07-29-2005 02:17 PM ET (US)            

I did not "admit" that my failures were my own damn fault - this somehow makes it sound like I reversed course after trying to blame a product manufacturer for my problems. I explained from the start that my problems were due to nonuse, and never tried to imply otherwise.

posted 07-29-2005 03:40 PM ET (US)            

Call the Outboard Motor Shop. For around $2000, they will swap out your carburetor 90-HP for a new Mercury 90 EFI. :)

posted 07-30-2005 07:59 AM ET (US)            

CASE AND POINT: Just for kicks, go over to The Hull Truth and monitor the BOATING message board for two whole weeks. In that time, you normally will see 4-5 people chime with an engine problem that, in many cases is their own fault and they are bashing the manufacturer. Here's a representative example,

SUBJECT: "Evinrude 250 is junk - HELP!"

Text: "Gang, I was out over the weekend and this peice of crap Evinrude started running rough at high rpm. It progressively got worse to the point where the engine stopped running and we had to get a tow home. I am totally pis$#@! off and will never buy another Evinrude as long as I live. My buddy's cousin had the same engine with the same problem - Evinrude has a problem on their hands!!!!"

Most of us are adept enough at critical thinking to ask the questions to get to the bottom of a thread like that. There are too many who are not though and will simply take this guy's statement as fact and start passing on a rumor that all Evinrude 250's are total junk. Oftentimes, what comes out in subsequent postings is the fact that the owner did zero maintenance and simply added gas and expected his engine to magically run like a top forever.

posted 07-30-2005 08:10 AM ET (US)            

It is also reasonable to expect that if you take a new motor to a dealer who is authorized to service it that they be able to find fundamental problems like mechanically disconnected throttle linkage between multiple carburetors.

I think it is reasonable to expect that a carburetor not become clogged repeatedly when its pattern of use is non-continuous. I think this expectation applies no matter what manufacturer made the carburetor, what continent it was made on, and who bolted it onto the engine.

I don't think it is reasonable to abandon all hope that an engine with a carburetor will operate reliably just because there is now a similar engine available with fuel injection. The existence of other technologies does not foreclose or prevent previous technologies from continuing to perform as they always did.

There are two possibilities here: the engine is not working as designed and has an problem that needs repair; or, the engine is working exactly as designed but the pattern of use is causing the problem.

If the engine has a problem that needs repair, the remedy is to get the problem diagnosed and fixed. Keep taking the engine back to the seller until he makes it run correctly.