Life with my carbureted Mercury/Yamaha FourStroke (continued)

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
pcrussell50
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Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby pcrussell50 » Sun Aug 07, 2016 7:44 pm

Back on the old forum, I started a running thread on my life with this motor that has given some folks in the past, trouble. It's a 2000 Mercury 90hp FourStroke (Yamaha powerhead), carbureted, powering my 1998 Alert 17 (special services classic Montauk).

Due to some things that come up in life, (fortunately none of them, bad), I haven't turned a prop in anger with that boat since summer 2013, which I wrote about back on the old forum in a thread of the same title. Fast forward 9 months to June 2014, after sitting unused the whole 9 months with nothing but Sta-Bil, I hadn't even drained the carbs... And it fired right up just like a car you drive every day. BUT, I didn't use it that day, or the rest of the summer because the grease in the tilt tube had turned to epoxy, and even the full pressure of the hydraulic steering couldn't budge it. So I put it away for the summer of 2014. In 2015, I ended up having to cut the steering rod off the tilt tube because most of it was frozen inside it. And Teleflex changed the design of their Baystar system and obsoleted any repair parts I needed, so I got a new cylinder and hoses which I am now ready to install.

1) So January 2016, with no steering, on nearly three year old fuel, I tried to fire it up on the muffs and it barely ran. I pulled the carbs on the spot and cleaned them and reinstalled them (about a three hour job, hurrying). Did not try to start it.

2) Just a few days ago, I put fresh gas in the tank, and? WOOT! It fired right up into a smooth idle like it had been doing it all along. YAY!

3) Yesterday, I used a $99 SyncPro motorcycle manometer to balance the carbs (fun and easy), enjoying every minute of listening to it's purr get better and better. Best advice I ever got on this forum to buy that, instead of the $1200 electronic factory balancing tool.

So that's where I am now. Going to hook up the new steering hoses and have fun Whalering with my 17 again. My trusty 13 Sport has been running like a champ the whole time, so it's not like I've done completely without.

More to come later


-Peter

Wweez
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby Wweez » Thu Aug 11, 2016 7:50 pm

Great to hear from you and your good experiences with the 90. I traded mine. It had a burned piston, in my opinion, from fuel starvation due to some blockage. I am sure, had I used it a lot more, It would have been a better engine. Had it been able to use real gasoline, not gubernment garbage, I would still have it. Thank you for all your good ideas and for sharing your experience. Good Luck, keep up the fun!

pcrussell50
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby pcrussell50 » Thu Aug 11, 2016 11:46 pm

Likewise, good to hear from you. Sorry to hear you had an expensive failure. And sorry to lose one of my stalwarts on the carbureted "Mercaha" team. What did you replace with? E-TEC 90's seem like the lightest option for a classic Whaler that was never designed for the weight of a four-stroke-cycle outboard.

A carb jet blockage of course could result in a burned piston, which you would think occurs while on the main jets at high rpm or load. Whereupon you might think that if a main was clogged, the smaller mids and idles would clog first, telegraphing pending trouble. Of course, nothing says it couldn't have been a random piece of debris, rather than a progressive accumulation of residue.

We spent the month of July this year in San Carlos, Mexico. I had my 13 Sport with oil injected Yamaha 40hp, two-stroke-cycle. And we made friends with a local boat mechanic, who had extra storage space in his boat yard, where we kept our trailers. In his yard was a carbureted Mercury FourStroke 75, like our 90's, on the back of a panga. I asked him what he thought of them. He said, "Yamaha powerhead, with carburetors. Good. Very very good.". He was both enthusiastic and certain. I suspect, that in his mind, they were pretty straightforward to tune and maintain in a third world country where they get used almost daily, by fishermen. Also, Mexico has good gas unadulterated by alcohol.

Jim put forth an idea about how to avoid residue-related clogging:. Keep the bowls full. Full bowls = no dried up evaporated fuel residue. As an added step, I might even pump the bulb firm every so often just to make sure, and maybe even loosen the drain plugs when I do, to circulate some fresh fuel into the bowls, before re-tightening the drains... Just an added thought.

-Peter

jimh
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby jimh » Sat Aug 13, 2016 10:20 am

When I had a six-carburetor V6 c.1992 Evinrude engine, I always tried to keep the engine in a normal operating position, as vertical as possible, when in storage. I would pump the primer bulb to keep the bowls full of gasoline. There was enough clearance on the trailer for the engine to sit in an operating position, but you could not move the trailer much. Any little slope or dip would result in the skeg hitting. But for sitting all winter, or for extended periods, keeping the engine vertical and the carburetor bowls filled worked well. The engine would typically start right up.

I see some fun in keeping an older carburetor engine running these days, and particularly so now that gasoline prices are back to the $2-per-gallon range. I only get about 50-hours of operation a year, and you cannot really consume a lot of fuel in that amount of time, even with a thirsty six-carburetor V6.

pcrussell50
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby pcrussell50 » Sun Jun 18, 2017 1:47 pm

When we last left off, it was late summer 2016. [See earlier posting for details.] The boat sat since then with the carburetors and fuel tank drained.

Recently, I finally broke out our classic Montauk-Alert 17. I put in fresh gasoline, pumped the primer bulb firm--I had to pump a lot because the carbs were empty. I clamped on the muff adaptor and turned the key. Two or three rotations of the crank and the Mercury 90-HP four-stroke-power-cycle engine [with Yamaha powerhead with carburetors] fired into a steady, smokeless idle--as if it were EFI. Back in business.

Even though I also have a nice classic 13 and another brand of speed boat (essentially a bass boat hull, with seats instead of casting decks and livewells), I had been missing my Montauk-Alert. I took out my wife and two little girls, age three and seven, to enjoy the warm water on Lake Mead. I had to pry them away when it was time to go--as it should be:

Image

Still not missing electronic fuel injection as long as this engine keeps running like this with simple maintenance.

-Peter

FISHNFF
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby FISHNFF » Tue Jun 20, 2017 1:52 am

Hey Peter!
Glad that motor still purrs and you are still loving that hull! I still believe that particular 17 is the best riding Classic 17 around!

It still looks great. Even the Merc stickers look good.

That boat has gone all over and done a lot. Glad it's still making people happy!

Remember you gotta call me if you ever sell!!!


FISHNFF

swist
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby swist » Thu Jul 13, 2017 7:39 am

I believe I was one of the original contributors to that thread [from the old forum]. I've been away for a while. But to summarize, I basically kept that thing going until 2015 with a cocktail of additives, completely draining the fuel out of the carbs in the off season and other care by a really good Mercury tech.

However in the Summer of 2015 it died a horrible death with a cracked block. I would guess about 400 hrs on the engine. I repowered with a 2016 EFI 90 hp command thrust Merc. I got a good deal and thought I'd save money by not having to rerig.

The new engine bears little resemblance to the old. Just looking under the cowl, it has so many fewer moving parts and fewer "things" apparently stuck on everywhere and actually looks quite elegant.

Some of us kept our Yamamercs running, but there was no getting around the fact that they were engineering "kludges" as we used to say at work.

jimh
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby jimh » Thu Jul 13, 2017 7:50 am

Mentioned several times, the discussion on the old forum that preceded this current discussion is still archived and available at

http://continuouswave.com/ubb/Forum3/HTML/020236.html

pcrussell50
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby pcrussell50 » Thu Jul 13, 2017 10:54 am

swist wrote:I believe I was one of the original contributors to that thread [from the old forum]. I've been away for a while. But to summarize, I basically kept that thing going until 2015 with a cocktail of additives, completely draining the fuel out of the carbs in the off season and other care by a really good Mercury tech.

However in the Summer of 2015 it died a horrible death with a cracked block. I would guess about 400 hrs on the engine. I repowered with a 2016 EFI 90 hp command thrust Merc. I got a good deal and thought I'd save money by not having to rerig.

The new engine bears little resemblance to the old. Just looking under the cowl, it has so many fewer moving parts and fewer "things" apparently stuck on everywhere and actually looks quite elegant.

Some of us kept our Yamamercs running, but there was no getting around the fact that they were engineering "kludges" as we used to say at work.


Welcome to the new board! Yes, you were a contributor to this thread and others concerning this motor. Thanks for your input over the years. 400 hours seems an early and untimely death. Mine is close to 900 these days. Yamamerc or Mercaha? Either way. There was a lot of confusion early on about the powerhead and how it differs from Yamaha, but in the end, it was much adieu about nothing. I don't think these motors are kuldgey, (we use that term too, in sports car racing), because the powerheads themselves are pure Yamaha. In fact, even though Mercury calls them a 90hp, these powerheads are actually complete Yamaha F100's. So much so, that when I take the motor for service that I don't perform myself, I take it to the Yamaha dealer, who uses his Yamaha service manual for the F100. Also, when I order powerhead parts, I order them from Yamaha, where they are actually cheaper than getting them from Mercury. Anyhow, I just wanted to clear the air on the hybrid brand nature of this motor. The powerhead is pure Yamaha through and through, not a mix. I'm less sure about the mid and lower. They may be actual Mercury. In fact, I suspect they are. But they are pretty straightforward, too.

Enjoy you new motor like I know you are :)

-Peter

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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby jimh » Thu Jul 13, 2017 1:25 pm

When Mercury bought thousands of power heads from Yamaha to use in their four-stroke-power-cycle outboard engines under the model descriptor of "FOURSTROKE", they typically mated the power head to a Mercury midsection, Mercury transom mount and power trim-tilt, and Mercury lower unit or gearcase. They also generally changed the electrical wiring harness so it had Mercury-style connectors and could mate to a Mercury rigging harness, ignition key switch, and gauges.

I have collected some information over the years about the Mercury-branded Yamaha-powerhead four-stroke-power-cycle 90-HP engines sold under the Mercury brand as 90 FOURSTROKE models. See

A Brief History of the Mercury 90-HP FOURSTROKE
http://continuouswave.com/forum/viewtopic.php?f=4&t=2405

Wweez
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby Wweez » Wed Jul 19, 2017 10:25 pm

Peter,
It has been too long since I checked on these posts. Great news of your experiences with the carb 90. You always did your homework and kept up with maintenance.
As I said last year, I am sure m experience could have been better with more work on my part. Once the bad gs fromone marina had tainted the situation, I never got on top of the game again. So very many of the subjects posted here and other sites are really maintenance related as I experienced.
I put an E-Tech 90, on the 170 and it has been fine. It starts! And for what they cost, it should.
Have not put it to enough use, but all is well.
Keep up the good work and enjoy the good life. Thank You for your continued help.

pcrussell50
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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby pcrussell50 » Fri Aug 09, 2019 12:33 am

Aaand...

After yet another two year hiatus, stored with the fuel tank and carburetors drained and the drain screws loose, I filled the tank with fresh gas, (and my additive cocktail), closed the carburetor drain screws, pumped the bulb firm and she started almost as if she had been used yesterday. Then I took her out on the lake today and went several miles, beached, swam, fished, picnicked, and drove several miles back... without a hiccup.

Still, this motor retains my opinion that it has many of the benefits of EFI, but with user serviceability. If there is a way this differs from the refinement EFI in daily operation, I have yet to see it. Amazing. Loving it.

-Peter

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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby jimh » Fri Aug 09, 2019 9:43 am

PETER--thanks for the further update. Simplicity and ease of repair has benefits.

ASIDE: I was thinking about buying a somewhat fancier than usual car, perhaps an Audi or something. I came across this motto: "Never own a German automobile that is out of warranty." I think there is some truth in that. Modern outboard engines are now rather complex and unrepairable.

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Re: Life with my carbureted Mercury/Yamaha FourStroke (continued)

Postby biggiefl » Tue Aug 13, 2019 9:52 am

I have 3 German cars that are out of warranty and have been so for years/decades....I must disagree Jim.

Dave Neal has the Yamaha 100hp version carbed and I think it has over 4k hours on it.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall. :roll: