The Missing Leak

By Tom Neale, 8/23/2007


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Looking into fluid reservoir

After covering thousands of miles at 8 knots, it’s incredibly great to get into our 1985 twenty foot Mako and head out a river at 30. But the Yamaha (200 HP) outboard is of 1985 vintage too, and before we bought it, it didn’t have a lot of tender loving care. So each Mako season (summer times) I go through a ritual of trying to give that hunk of metal enough TLC to make up for all the care she’s missed and to get her ready to run. It hasn’t always been easy and this time was no exception.

The job seemed to go well. (Never believe that about an outboard job.) After changing the lower unit gear case oil, lubing, changing filters etc, etc, I juiced up the battery and hooked up a hose connector to the water intake while the boat was still on the trailer. I’d never go through the hassle of a launch without starting the engine like this. I know you gotta have faith about outboards but I’m not that stupid (or so I like to think.) She fired right off. “Hallelujah! Let’s get this baby in the water.” I’d lowered the engine with the hydraulic tilt system to start it, and so I raised it again for the ride to the ramp. That equipment worked just as it should have. I thoroughly sprayed all the right parts of the outboard and more with StarBrite Corrosion Spray Lube. This included the electric hydraulic tilt motor which had sported a healthy “protective” coating of rust when I got the boat a few years ago. It also included various parts of the mounting bracket. Then we hitched her up and headed for the ramp.

Whenever you launch a boat after regular maintenance like this, it’s inevitable that you’re going to see just a little sheen on the water. I’m always ready with an absorbent pad such as those from StarBrite. They soak up any oil or fuel but not water. If it’s just a tiny amount of residual oil, you can tear off a small section of the pad and use that. When we launched I noticed the usual slight sheen, took care of it, started the engine, thrilled to the roar, and took off for open water where I could blow the spider webs out of the carburetors and let those old pistons and valves flex their muscles. It was as good as it could be.

About Cheating Bars

1. A cheating bar is something that you shouldn’t use, but that most mechanics end up using occasionally.

2. It’s essentially a metal pipe that you can fit over your wrench or over the ratchet handle of a socket wrench. It’s considerably longer than the tool with which you use it, thus providing much greater leverage. How much longer depends on how much you want to risk REALLY messing things up.

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When I got back to the dock and shut her down, I noticed another small sheen after I tilted the engine. I figured it was still residue from my lube and spray maintenance, soaked it up, and forgot about it. The next day Mel and I went for a ride. When I lowered the engine I noticed another very tiny sheen—almost invisible, but there. We had a great ride. When we were back at the dock I tilted the motor and it made it almost all the way up and stopped, refusing to move either up or down even though the hydraulic motor was running. And there was another almost imperceptible sheen. With the help of a friend, we ignominiously towed the Mako back to the ramp, hauled it out and brought it back for work. I was thinking, “If I can’t fix this no one else will because the parts and labor are probably worth too much for the age of the engine.” In other words, no more fast Mako rides until I win the lottery because I sure can’t afford another outboard.

I removed the fill plug for the tilt motor fluid and, with a tiny “Stylus Reach” mechanics’ light by Streamlight, Inc., looked in. The chamber was empty. “Must be a leak somewhere. Maybe that’s where the sheen came from.” I filled the chamber, let the air bleed out and the motor began tilting again. I looked closely at the tilt mechanism as I raised and lowered the engine and I saw absolutely nothing. No leaks. My hopes rose. (You have to do a lot of unrealistic hoping when you have an outboard engine that old.) Then I noticed something very strange.

On a small bolt at the bottom of the left fork of the mounting bracket, I saw a bead of oily fluid. I zeroed in. This bolt had nothing to do with the tilt hydraulics. It wasn’t even below the tilt motor, lines, ram or any other part of the system. It was screwed into solid metal, nothing hollow. So hydraulic fluid couldn’t have dripped onto that little bolt or migrated there or found its way via an inside passage or gotten there any other way. It must be left over from my corrosion spray, I hoped. But it sure looked like hydraulic fluid to me. And smelled like it. But this would have been impossible.

I wiped off the drop and operated the tilt motor again while standing on the ground alongside the engine, watching the system closely. Nothing. No leaks. But when I shifted my gaze to that bolt, there was another bead of oil. “This is crazy,” I thought. I wiped it off again and operated the tilt again. And again, no leaks anywhere. And again, a drop materialized on that little bolt! By this time I was beginning to think I was going nuts, an easy thing to do when you mess with outboards.

So I crouched down with my face a little over a foot from the bolt, and asked Mel to operate the tilt as I watched intently. As before, a bead formed on the bolt. But something else happened. I noticed the finest of specks of something on my glasses. I took them off, wiped the specs and they seemed to be oil. I was beginning to wonder if the engine was haunted by a poltergeist. I wiped off the drop from the bolt, placed my finger on it, and operated the tilt motor again. There was no bead on the bolt, but my hand was oily. I looked again, even closer, as the tilt motor whirred. A fine mist of oil was almost invisibly splattering from the side of the bolt. When I placed a small board between it and the bottom of the ram and shocks, it splattered on the board. Finally I realized that a small almost invisible stream of fluid was being sprayed across space, from a curled stainless high pressure hydraulic pipe under the ram. It was hitting the bolt. This only happened when the tilt motor was operating. The pin hole in the pipe was so small I couldn’t see it no matter how closely I looked. VIOLA!

New line, old motor, and dripping bolt lower left

The line cost under $30.00. I ordered it from Jetts Marine in Reedville, VA and had it in 3 days. Getting the old one out was a job because it was stainless threaded into aluminum and somebody else had already messed with it at some point in the past. After a lot of PB Blaster and tapping and careful use of a “cheating bar” I backed out the compression fittings at both ends. Getting the new pipe (line) on took an hour or so because the pipe didn’t line up perfectly with the ports and I had to be extremely careful not to strip the threads. Then I had to refill and let it bleed, which involved removing the filler plug several times. This, too, had been messed with earlier in its life and, before the job had even started, I noticed that the 17 MM bolt head was slightly rounded. Before the job ended, the socket wrench slipped and the entire thing was rounded. It was carefully machined aluminum and very soft. I removed the stub with a stud remover by Irwin, especially designed to handle that sort of disaster. I called Jetts Marine and they called back saying, “No, we don’t have a new one of those but we’ve got a good used one with a new O ring, come on over.” I did, and was soon back in business.

If I’d had to pay a shop to do this they would have justifiably charged a small fortune. This would have substantially cut into the unjustifiably large fortunes I pay for gas every time I pull up to the fuel dock. I don’t know what’s going to happen next with that engine, but I guess that’s good. It means I’ve got a great excuse to get out and run it while I can before something breaks again.

You may be able to just pay the money and buy new outboards or get mechanics to fix whatever happens. If you are, I envy you. But if you’re like me and just can’t, you still have a good chance of keeping them going and keeping the fun coming if you’re stubborn, invest in good tools, take your time to figure out what’s going on, don’t mind getting dirty and never start thinking that machines are magical—except sometimes.

Copyright 2004-2008 Tom Neale