Like why even try it?
I had a frightening experience while attempting to hand-crank start a 7 hp Yanmar on our Hunter 27 (Ocean Gypsy) in 1976 off Fajardo Puerto Rico. It's one of those mistakes that you never forget. It's been awhile since I told this story but I'll give it a go this morning while the coffee pot is brewing.
My wife and I woke up that morning on the hook near the east end of Puerto Rico. That’s when I got the bright idea to practice hand crank starting my diesel. The thought process at the time was just to know how to do it in case of an emergency befalling us at some point in the future when we least expected.
It was one of those lazy cruising mornings when you're sitting around enjoying the sunrise and the moment on the water, but being young and energetic - thinking of all the things that needed to be done or the things one thought ought to be done.
So I justified it in a matter of a few minutes that knowing how and having the experience of successfully starting the diesel by hand cranking, was somehow elevated from nice to know to need to know.
My qualifications or should say rationalizations for thinking little of the physical challenge and requirements for the job of hand cranking a small diesel went something like this. I had been on the wrestling team while in high school and while in college and had in the not too distant past been fairly used to some pretty difficult physical stresses. And I'd easily kick-started a big Harley XLCH every day the previous year and rode it to work at an oil refinery in Wilmington California while living on the beach in Redondo. Since it was the only transportation I had at the time (it never rains in Southern California - right). I had even taught my 14 year old little bother who was visiting me that summer who weighed about 100lbs at the time, how to kick-start the Harley using momentum and technique. So I figured hand cranking a 7 hp Yanmar diesel would not be too serious of a challenge.
Back then we didn't have Bowflex, but if we had I could have qualified to make a Bowflex commercial appearance with my shirt off as I was more than a little ripped. Now-a-days I'm so old and flabby that my 5 year old grandson and I work out with the 15 lbs. dumbbell in the garage that I bought for my wife a few years back. And we think we've had a serious work out. He and I are equally matched so we make good work-out buddies.
But back then things we're different, like everybody is young once upon a time, and so shucks the thought of giving the Yanmar a go didn't seem like a serious concern.
The engine cover doubled as the stairway from the cabin up through the companion way into the cockpit. So I took the engine cover off and sat it behind me in the cabin. Then placed the hand crank on the flywheel fitting on the front of the engine, depressed the decompression chamber lever and started to crank for all I was worth. In a very short time the flywheel was moving faster than the engine was ever designed to run. About the time the flywheel couldn't possibly go any faster even if Arnold Schwarzenegger was cranking it, I released the decompression lever and continued to forcibly follow through and apply pressure with the crank motion. Then all of a sudden the strangest thing happened. Not only did I not successfully force and move the piston through the compression stroke, but it kicked back with such force and with enough power that it went through the compression stroke in reverse and the engine started and was now running in reverse stroke.
If I remember correctly, similar to the kick start on the Harley, the Yanmar diesel engine hand crank was designed to apply force in only one direction and had a screw type fitting where it attached to the flywheel which had the result of releasing when and if it kicked back. Which it did quite violently, but the crank design saved me from having been physically punished for my mistake. But I suddenly had a much different problem.
The engine was running in reverse stroke. It was choking, and coughing and sputtering but it was running in reverse stroke. For those that can’t imagine what this was like, may I try to explain it further. The engine was sucking intake air through the cooling water and engine exhaust line on the transom at the water line. And it was exhausting carbon monoxide diesel smoke fumes into the cabin though the air intake scooper mounted on the side of the engine. Which was the reason for it not running smoothly to say the least, but it was running. It was kind of like having down in the boat cabin an unfriendly fire-breathing dragon right in your face, and the dragon needed to be immediately slayed to save life and limb. The problem was compounded by the obvious escape routes being temporarily blocked (so running away was not an option). Behind me was the stairway engine cover blocking my retreat in that direction and ahead of me was the dragon requiring a high jump to leap over it and into the safety of the cockpit. Not to mention my frantic wife, wide-eyed but thankfully saying nothing while patiently waiting to be rescued. So my otherwise peaceful sunrise on the hook while cruising in the Caribbean had suddenly turned into a nightmare reality show.
Now at that point I could have leaped the beast, climbed into the cockpit, gone quickly forward, raised the anchor then returned to the cockpit and put the transmission gear in reverse and the boat would have traveled in a forward direction. Then I could have perversely claimed victory at having started the engine using the hand crank and in the process actually made some forward progress. However, my wildly racing thoughts at that instance were more on how to immediately stop the engine and hopefully salvage it from total destruction. My second concern of course was rescuing my wife.
Luckily no saltwater made it far enough up the exhaust line to actually enter the engine cylinder or the engine would have needed to be replaced. My wife did this once recently in her automobile, a Saturn Vue. She drove through a deep water puddle in a rain storm, deep enough to suck water into the air intake. Once a drop of water reaches the piston head the water doesn’t compress and the engine abruptly stops, with the results usually being a bent rod and or a bent crank shaft. After that if the engine will run at all it never runs quite right again (it shakes a little).
Back to the Yanmar and my 1976 emergency, I quickly deduced that to stop a diesel running in reverse stroke one would have to apply the same method needed to stop a diesel running in normal stroke, which was to put the fuel lever in the off position. Starve the beast!!!
It worked! The engine stopped. So now what? Thoughts racing again I quickly deduced the best medicine would be to start the engine in a more traditional approach using the electric starter and if it would start and run then let it run awhile and hopefully it would “clean” itself of whatever may have been sucked in through the exhaust. So that’s what I did.
It worked and ran ok and everything sounded fine. So after letting it run awhile I shut it down and got on the radio ship to shore channel and called a Yanmar dealer somewhere in Puerto Rico for advice. As many of you may know the 7 hp Yanmar was a single cylinder engine and nearly indestructible. The dealer told me I did exactly what he would have recommended to restart and run the engine in normal mode and let it run awhile. He then said there were only about 4 or 5 moving parts in the engine and to destroy it I would have had to use a grenade. He reassured me that the engine was going to be ok.
So if you attempt to start your marine diesel using the hand crank method I wish you luck. But if you've read this far, hopefully you were mildly entertained and may have learned something from my mistake. Like why even try it?
Kindest Regards,
JonBill
I can just have my wife get behind the boat and swim real fast and push the boat until I get it started. I may just save the juice in the batteries and have her do that anyway.
