I'm trying to decide if I've got my YSM12 running at optimum. The hull speed I understand is 6.5 for a Hunter 30 1983. I might be dealing with a sticky Governor also??? I can cruise at 5 knots. If I push it harder it starts to smoke. Sound about right?
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J
Jim
Watch that tach
Don't go by speed. There are to many things that can affect speed. Your tachometer will tell you everything you need to know about performance. This has been hashed over many times. Check the Forums. Most Yanmars should run 3400 to 3600 RPM's under load. If you are not close to that and smoking, there is a good chance you are over propped [to high pitch] or your mixing elbow is plugged. If your tach is not working, you will only be guessing. Check the Forums.
Don't go by speed. There are to many things that can affect speed. Your tachometer will tell you everything you need to know about performance. This has been hashed over many times. Check the Forums. Most Yanmars should run 3400 to 3600 RPM's under load. If you are not close to that and smoking, there is a good chance you are over propped [to high pitch] or your mixing elbow is plugged. If your tach is not working, you will only be guessing. Check the Forums.
They don't have tachs!
Jim: The problem with these order Yanmars is that they did not come with a tach. Steve: Once you start smokin' you are pushing her too hard. There was a post in the last couple of months for a tach that you could use on these engines. You may want to search around. They were inexpensive and worth giving it a try. It is hard to tell if you are having other problems without a tach, so I would suggest that you start there and then you can better diagnosis what other problems you may be having. It could be a dirty bottom, fouled prop.......... or who knows what!
Jim: The problem with these order Yanmars is that they did not come with a tach. Steve: Once you start smokin' you are pushing her too hard. There was a post in the last couple of months for a tach that you could use on these engines. You may want to search around. They were inexpensive and worth giving it a try. It is hard to tell if you are having other problems without a tach, so I would suggest that you start there and then you can better diagnosis what other problems you may be having. It could be a dirty bottom, fouled prop.......... or who knows what!
B
Bob F
What's your hurry?
Remember this is a sailboat. Whats your hurry? Rig a tach, test max RPM then keep it under 70-80% of max. By my calculations it only take you an extra 12 minutes to travel 6 nau. miles at 5 knts vs. 6 knts. Plus you'll save your engine.
Remember this is a sailboat. Whats your hurry? Rig a tach, test max RPM then keep it under 70-80% of max. By my calculations it only take you an extra 12 minutes to travel 6 nau. miles at 5 knts vs. 6 knts. Plus you'll save your engine.
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Ron Searcy
B
Bob Howie
YSM12 at optimum
Steve, I have a 78h30 that formerly had the YSM-12 engine in it til I finally got tired of wrenching on it and spent an obscene amount of money to repower the boat with some much better, much more reliable. I can almost hear the groans from my compatriots in this forum as they anticipate I'm about to launch into another diatribe about repowering older boats, but, out of respect for them, I'll forgo except to say if you are ever interested, just send me an email address and I will send you the file on that little adventure. Anyway, my boat had the tach in it and it seemed that about the best she would do was around 3,000 rpm. Got about 5 to 5.5 knots out of the boat at that setting which was right about the point where she would start to smoke and spit oil out the exhaust. My engine was pretty tired, too, so that might have had something to do with it. The talk about about being overpropped, in my opinion, is a little banal since you probably have a 13x13 two-blade prop under the water which was pretty much standard. I doubt your problem is overpropped; more like underpropped and over-rev'd. You're pretty close on your theoretical hull speed and remember, that's theorectical with all the advantages, i.e., clean bottom, clean, properly-pitched prop, true-running shaft, zero wind, zero current, figured in. Start knocking off points if any of these factors are absent. If you are getting between 5 and 5.5 knots, that's about it. A tip on engine oil...the manual on the YSM-12 is a little vague in what the oil level should be. You have two marks on your dipstick; one on the low end, one on the upper end. Yanmar's a little obtuse on where the oil should be, but, from experience, you want it NO higher than halfway between the two marks. Any higher and the damn thing could wind up running in engine oil and you won't be able to shut it off. The engine will run away and could fail catastrophically. I had this happen to me -- oops! too much oil in the sump -- and I was able to shut the engine down because I'd rigged an air shutoff valve...basically suffocated the thing. I suppose the YSM-12 is a good little engine, but parts are getting increasingly hard to find and they are getting expensive, too, and around here no one really wants to work on it. I opted just to finally switch mine out and pretty glad I did. Good luck with yours.
Steve, I have a 78h30 that formerly had the YSM-12 engine in it til I finally got tired of wrenching on it and spent an obscene amount of money to repower the boat with some much better, much more reliable. I can almost hear the groans from my compatriots in this forum as they anticipate I'm about to launch into another diatribe about repowering older boats, but, out of respect for them, I'll forgo except to say if you are ever interested, just send me an email address and I will send you the file on that little adventure. Anyway, my boat had the tach in it and it seemed that about the best she would do was around 3,000 rpm. Got about 5 to 5.5 knots out of the boat at that setting which was right about the point where she would start to smoke and spit oil out the exhaust. My engine was pretty tired, too, so that might have had something to do with it. The talk about about being overpropped, in my opinion, is a little banal since you probably have a 13x13 two-blade prop under the water which was pretty much standard. I doubt your problem is overpropped; more like underpropped and over-rev'd. You're pretty close on your theoretical hull speed and remember, that's theorectical with all the advantages, i.e., clean bottom, clean, properly-pitched prop, true-running shaft, zero wind, zero current, figured in. Start knocking off points if any of these factors are absent. If you are getting between 5 and 5.5 knots, that's about it. A tip on engine oil...the manual on the YSM-12 is a little vague in what the oil level should be. You have two marks on your dipstick; one on the low end, one on the upper end. Yanmar's a little obtuse on where the oil should be, but, from experience, you want it NO higher than halfway between the two marks. Any higher and the damn thing could wind up running in engine oil and you won't be able to shut it off. The engine will run away and could fail catastrophically. I had this happen to me -- oops! too much oil in the sump -- and I was able to shut the engine down because I'd rigged an air shutoff valve...basically suffocated the thing. I suppose the YSM-12 is a good little engine, but parts are getting increasingly hard to find and they are getting expensive, too, and around here no one really wants to work on it. I opted just to finally switch mine out and pretty glad I did. Good luck with yours.
R
Ron Searcy
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Donna
Jab at Bob Howie
Bob you really should let them know what the crew tends to do when ALL the symptoms of filling the oil to the top line start to happen!!
Bob you really should let them know what the crew tends to do when ALL the symptoms of filling the oil to the top line start to happen!!
B
Bob Howie
Mutinous Dogs
Hey, no fair! I know that "Donna of Kemah" who just posted that crack about what the crew does when you overfill the oil on the YSM-12 and the waves are a-rockin' when you leave the marina! Fine! As I so accurately alluded to the problem that occurs when one overfills the YSM-12 oil -- the warning about which is just a single line mired in quasi-obscurity in the English-translated ops/service manual of the Japanese-built-by-Toyota Yanmar YSM-12 -- is that the scupper picks up the engine oil and drains it into the YSM-12's single, horizontal cylinder causing the engine to start smoking amazingly and runs the engine at absolute full bore...as in as fast as the thing will go, thus precipitating a full-blown engine runaway that can't be shut off. You can pull the shut-off handle all you want and that does, in fact, shut off the diesel fuel to the engine, but the engine is now running on crankcase oil and it's an unnerving event that could actually lead to the engine failing catastrophically. Meanwhile, while the captain is trying to deal with this unexpected, albeit innocently-enough, self-induced dilemma, the crew -- bravehearts all that they are -- are donning life jackets and preparing to perform an uncommand, every-girl-for-herself abandon ship procedure, an ersatz "Been fun, Captain; See ya!" drill; huddled against the comming like rats looking to jump a sinking -- or about to explode, in their minds -- ship! Geez, Louise! Thanks for y'all's vote of confidence, y'motely crew! Pirates would not have phased them because they would have looked at it as just another maritime cool way to meet boys, but let the engine get a little jiggy and they all plan a day ashore shopping at the mall! Does anyone know the current day penalties for making a chicken-livered, mutinous crew walk the plank? Keelhauling? Hanging them from a yard arm? As captains, we can do that, can't we?
Hey, no fair! I know that "Donna of Kemah" who just posted that crack about what the crew does when you overfill the oil on the YSM-12 and the waves are a-rockin' when you leave the marina! Fine! As I so accurately alluded to the problem that occurs when one overfills the YSM-12 oil -- the warning about which is just a single line mired in quasi-obscurity in the English-translated ops/service manual of the Japanese-built-by-Toyota Yanmar YSM-12 -- is that the scupper picks up the engine oil and drains it into the YSM-12's single, horizontal cylinder causing the engine to start smoking amazingly and runs the engine at absolute full bore...as in as fast as the thing will go, thus precipitating a full-blown engine runaway that can't be shut off. You can pull the shut-off handle all you want and that does, in fact, shut off the diesel fuel to the engine, but the engine is now running on crankcase oil and it's an unnerving event that could actually lead to the engine failing catastrophically. Meanwhile, while the captain is trying to deal with this unexpected, albeit innocently-enough, self-induced dilemma, the crew -- bravehearts all that they are -- are donning life jackets and preparing to perform an uncommand, every-girl-for-herself abandon ship procedure, an ersatz "Been fun, Captain; See ya!" drill; huddled against the comming like rats looking to jump a sinking -- or about to explode, in their minds -- ship! Geez, Louise! Thanks for y'all's vote of confidence, y'motely crew! Pirates would not have phased them because they would have looked at it as just another maritime cool way to meet boys, but let the engine get a little jiggy and they all plan a day ashore shopping at the mall! Does anyone know the current day penalties for making a chicken-livered, mutinous crew walk the plank? Keelhauling? Hanging them from a yard arm? As captains, we can do that, can't we?
Do your passengers aboard those planes......
act in the same manner as those "Mutinous" passengers aboard your boat?
act in the same manner as those "Mutinous" passengers aboard your boat?
D
Donna
Of Course!!!
If the plane looks and sounds anything at all like that boat looked and sounded, give me a parachute and show me the way out!
If the plane looks and sounds anything at all like that boat looked and sounded, give me a parachute and show me the way out!
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