Can anyone tell me what's going on with my Yanmar engine? I have a 25D with a 1GM Yanmar engine. When I place the speed control lever in "full" position forward the engine makes only 2800 RPM. However, in "full" position back (reverse) it makes 4000 RPM. Anyone have any idea what's wrong?
merkulov@ix.netcom.com
Yanmar Engine Problem in my 25D Sailboat
Moderator: Jim Walsh
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Dean Abramson
Re: Yanmar Engine Problem in my 25D Sailboat
Petr,
Are you talking about in gear or in neutral? The way mine is set up, the in-gear/out-of-gear knob is "out" when in neutral, which physically blocks me from moving the throttle lever as far forward as I can in the reverse direction. For this very reason, I have taken to starting my 1GM by pushing the lever aft instead of forward; the extra "gas" starts it more quickly and cleanly, resulting in much less unburnt grundge coming out of the exhaust pipe to trash my transom, pollute the water, and scare the faint of heart. If your engine has this same disparity while in gear, I think it would have to be a cable problem, likely a slipping cable. For whatever reason, the cable is not pushing the throttle lever on the engine as far when you are in forward. See how the cable set-up works; pushing the lever aft shifts the transmission (via a separate cable) to Reverse, but still pushes the throttle cable the same direction (it's darn clever, actually). Then look at the engine while someone moves the lever; I'm pretty sure that you will see that the throttle lever on the engine is not moving as far when your mate pushes the cockpit control forward, as opposed to aft. The engine, of course, turns the same direction in both gears, and the throttle lever on the engine only moves in one direction. I think you have a problem that is pretty easy and cheap to fix. (If you only have the problem in neutral, then you probably have no problem at all, at least if it is set up like mine...) And if you get 4000 rpm, it sounds like a nice healthy engine. I would be interested to know how many revs you get under load (in gear); I barely get over 3100 under load in mine now, but it still pushes the boat very easily at hull speed. And against a stiff chop, I've motored signifigantly faster than a CD36 and a CD30 I was traveling along with. I LOVE my boat! By the way, I don't think that my starting procedure is exactly Yanmar-approved. But an employee at the boat yard heard my long-laboring starter and saw the ugly scene at the stern, and said "That's an old engine. Give er more gas!" I thought, hmmm, the only way to do that, in neutral (since that pesky knob is in the way), is to push the lever BACK. Nowadays my transom, my starter and my neighbors love me more. But probably I really could use a tune-up or re-build. I'll trade you MY cables for YOUR engine! Please let me know what you find out.
And if you are out there tooling around at 4000 rpm, in gear, in reverse, then please let me know WHERE, so I can keep my distance! And email me some steering tips.
Dean Abramson
"Mariah"
CD25D
dabramson@mainephoto.com
Are you talking about in gear or in neutral? The way mine is set up, the in-gear/out-of-gear knob is "out" when in neutral, which physically blocks me from moving the throttle lever as far forward as I can in the reverse direction. For this very reason, I have taken to starting my 1GM by pushing the lever aft instead of forward; the extra "gas" starts it more quickly and cleanly, resulting in much less unburnt grundge coming out of the exhaust pipe to trash my transom, pollute the water, and scare the faint of heart. If your engine has this same disparity while in gear, I think it would have to be a cable problem, likely a slipping cable. For whatever reason, the cable is not pushing the throttle lever on the engine as far when you are in forward. See how the cable set-up works; pushing the lever aft shifts the transmission (via a separate cable) to Reverse, but still pushes the throttle cable the same direction (it's darn clever, actually). Then look at the engine while someone moves the lever; I'm pretty sure that you will see that the throttle lever on the engine is not moving as far when your mate pushes the cockpit control forward, as opposed to aft. The engine, of course, turns the same direction in both gears, and the throttle lever on the engine only moves in one direction. I think you have a problem that is pretty easy and cheap to fix. (If you only have the problem in neutral, then you probably have no problem at all, at least if it is set up like mine...) And if you get 4000 rpm, it sounds like a nice healthy engine. I would be interested to know how many revs you get under load (in gear); I barely get over 3100 under load in mine now, but it still pushes the boat very easily at hull speed. And against a stiff chop, I've motored signifigantly faster than a CD36 and a CD30 I was traveling along with. I LOVE my boat! By the way, I don't think that my starting procedure is exactly Yanmar-approved. But an employee at the boat yard heard my long-laboring starter and saw the ugly scene at the stern, and said "That's an old engine. Give er more gas!" I thought, hmmm, the only way to do that, in neutral (since that pesky knob is in the way), is to push the lever BACK. Nowadays my transom, my starter and my neighbors love me more. But probably I really could use a tune-up or re-build. I'll trade you MY cables for YOUR engine! Please let me know what you find out.
And if you are out there tooling around at 4000 rpm, in gear, in reverse, then please let me know WHERE, so I can keep my distance! And email me some steering tips.
Dean Abramson
"Mariah"
CD25D
Petr Merkulov wrote: Can anyone tell me what's going on with my Yanmar engine? I have a 25D with a 1GM Yanmar engine. When I place the speed control lever in "full" position forward the engine makes only 2800 RPM. However, in "full" position back (reverse) it makes 4000 RPM. Anyone have any idea what's wrong?
dabramson@mainephoto.com
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vinnie
Re: Yanmar Engine Problem in my 25D Sailboat
Peter/Dean,
I have essentially the same problem with my 1GM engine. My MAX. numbers were: 2400 RPM in forward gear and 3600 RPM in reverse gear or neutral reverse. I had the hull cleaned last week. The diver told me that he removed a heavy barnicle build up from the prop. I though this would solve the RPM problem while improving the sluggish performance of the boat. Unfortunately, the forward RPM increased only 400 RPM to 2800, however, the boat does motor and preform much better. So, now I'm faced with a list of troubleshooting tasks starting with the throttle cables and who knows what else. If any one can point me the right direction on this, I would appreciate it. By the way, when I bought my boat, the previous owner instructed me to start the engine in neutral and with the throttle BACK in reverse. Engine starts fine.
Vinnie
S/V "Osprey"
1982 Hull#86
vgennaro@wpmedia.com
I have essentially the same problem with my 1GM engine. My MAX. numbers were: 2400 RPM in forward gear and 3600 RPM in reverse gear or neutral reverse. I had the hull cleaned last week. The diver told me that he removed a heavy barnicle build up from the prop. I though this would solve the RPM problem while improving the sluggish performance of the boat. Unfortunately, the forward RPM increased only 400 RPM to 2800, however, the boat does motor and preform much better. So, now I'm faced with a list of troubleshooting tasks starting with the throttle cables and who knows what else. If any one can point me the right direction on this, I would appreciate it. By the way, when I bought my boat, the previous owner instructed me to start the engine in neutral and with the throttle BACK in reverse. Engine starts fine.
Vinnie
S/V "Osprey"
1982 Hull#86
Dean Abramson wrote: Petr,
Are you talking about in gear or in neutral? The way mine is set up, the in-gear/out-of-gear knob is "out" when in neutral, which physically blocks me from moving the throttle lever as far forward as I can in the reverse direction. For this very reason, I have taken to starting my 1GM by pushing the lever aft instead of forward; the extra "gas" starts it more quickly and cleanly, resulting in much less unburnt grundge coming out of the exhaust pipe to trash my transom, pollute the water, and scare the faint of heart. If your engine has this same disparity while in gear, I think it would have to be a cable problem, likely a slipping cable. For whatever reason, the cable is not pushing the throttle lever on the engine as far when you are in forward. See how the cable set-up works; pushing the lever aft shifts the transmission (via a separate cable) to Reverse, but still pushes the throttle cable the same direction (it's darn clever, actually). Then look at the engine while someone moves the lever; I'm pretty sure that you will see that the throttle lever on the engine is not moving as far when your mate pushes the cockpit control forward, as opposed to aft. The engine, of course, turns the same direction in both gears, and the throttle lever on the engine only moves in one direction. I think you have a problem that is pretty easy and cheap to fix. (If you only have the problem in neutral, then you probably have no problem at all, at least if it is set up like mine...) And if you get 4000 rpm, it sounds like a nice healthy engine. I would be interested to know how many revs you get under load (in gear); I barely get over 3100 under load in mine now, but it still pushes the boat very easily at hull speed. And against a stiff chop, I've motored signifigantly faster than a CD36 and a CD30 I was traveling along with. I LOVE my boat! By the way, I don't think that my starting procedure is exactly Yanmar-approved. But an employee at the boat yard heard my long-laboring starter and saw the ugly scene at the stern, and said "That's an old engine. Give er more gas!" I thought, hmmm, the only way to do that, in neutral (since that pesky knob is in the way), is to push the lever BACK. Nowadays my transom, my starter and my neighbors love me more. But probably I really could use a tune-up or re-build. I'll trade you MY cables for YOUR engine! Please let me know what you find out.
And if you are out there tooling around at 4000 rpm, in gear, in reverse, then please let me know WHERE, so I can keep my distance! And email me some steering tips.
Dean Abramson
"Mariah"
CD25D
Petr Merkulov wrote: Can anyone tell me what's going on with my Yanmar engine? I have a 25D with a 1GM Yanmar engine. When I place the speed control lever in "full" position forward the engine makes only 2800 RPM. However, in "full" position back (reverse) it makes 4000 RPM. Anyone have any idea what's wrong?
vgennaro@wpmedia.com
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Scott Ritchey
Re: Yanmar Engine Problem in my 25D Sailboat
Look at your transmission gear reduction ratios. Reverse usually has a greater reduction ratio; so engine RPM is higher for the same prop RPM.
RitcheyVS@aol.com
Petr Merkulov wrote: Can anyone tell me what's going on with my Yanmar engine? I have a 25D with a 1GM Yanmar engine. When I place the speed control lever in "full" position forward the engine makes only 2800 RPM. However, in "full" position back (reverse) it makes 4000 RPM. Anyone have any idea what's wrong?
RitcheyVS@aol.com
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AR Marine Service
Re: Yanmar Engine Problem in my 25D Sailboat
You are over propped or the prop is fouled. It's as simple as that!!!
With a 1GM Yanmar you should see 3600 rpm at max throttle in gear underway (Fwd) The trans has a different reduction ratio in reverse than fwd. But this has nothing to do with it. You should not be worried about what rpm you get in reverse. It is irrelevant.
Call me if you need more details. 281-334-9211 Rodney
rodney@armarineservice.com
With a 1GM Yanmar you should see 3600 rpm at max throttle in gear underway (Fwd) The trans has a different reduction ratio in reverse than fwd. But this has nothing to do with it. You should not be worried about what rpm you get in reverse. It is irrelevant.
Call me if you need more details. 281-334-9211 Rodney
Petr Merkulov wrote: Can anyone tell me what's going on with my Yanmar engine? I have a 25D with a 1GM Yanmar engine. When I place the speed control lever in "full" position forward the engine makes only 2800 RPM. However, in "full" position back (reverse) it makes 4000 RPM. Anyone have any idea what's wrong?
rodney@armarineservice.com