I am new to the Diesel engine. There seems to be a lot of vibration coming from the engine. A dock partner said that is typical, and some one sailing with me said it sounded like a bit much. Is there a way to measure?
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I'm guessing you have the 2GM20.
Yanmar 2 cyl all run a bit lumpy but there are a number of things that can affect the smoothness of operation. Prop selection and condition, engine alignment, prop shaft condition and engine mount condition all play a part. Try running your engine up slowly to ~3000 RPM in neutral at the dock. That'll give you an idea of how the engine behaves w/o most of the other parts of the propulsion system playing a part.
Yanmar 2 cyl all run a bit lumpy but there are a number of things that can affect the smoothness of operation. Prop selection and condition, engine alignment, prop shaft condition and engine mount condition all play a part. Try running your engine up slowly to ~3000 RPM in neutral at the dock. That'll give you an idea of how the engine behaves w/o most of the other parts of the propulsion system playing a part.
Clark hit it on the head for you.
Diesels all have certain rpms that cause vibrations. The fewer the cylinders the rougher they are. The cleaner and more balanced the drive components the smoother they are. Check alignment, tightness of motor mounts, and condition of the cutless bearing all count. For example, at a certain rpm my two cylinder Yanmar vibrates the hasp lock on one of my cockpit lockers...no big deal, I just avoid that rpm.
Diesels all have certain rpms that cause vibrations. The fewer the cylinders the rougher they are. The cleaner and more balanced the drive components the smoother they are. Check alignment, tightness of motor mounts, and condition of the cutless bearing all count. For example, at a certain rpm my two cylinder Yanmar vibrates the hasp lock on one of my cockpit lockers...no big deal, I just avoid that rpm.
Need more info
This could be just about anything. If it only happens when you moving: Prop might have electrolisis. Might be barnacles on the prop. Might be the cutless bearing. If it happens in neutral as well it might be engine alignment, engine mounts - if the mounts go soft on you the engine will dance all over the place.
This could be just about anything. If it only happens when you moving: Prop might have electrolisis. Might be barnacles on the prop. Might be the cutless bearing. If it happens in neutral as well it might be engine alignment, engine mounts - if the mounts go soft on you the engine will dance all over the place.
mounts - how old is too old
My H28.5 is getting on in years and I got to wondering about the motor mounts after reading a few weeks back about the tink tink someone heard and found to be a shot mount. So assuming that these rubber mounts vulcanize and may shrink over the years... are they just shot or does one just do the realignment. I checked Mack Boring ( a yanmar dealer) and they want $119 "each" for the (2)100 lbs and (2)75 lbs mounts on the 2GMF! sounds a bit rich for a flanged metal with rubber stopper. How many of you have "remounted" or just "adjusted" and has the readjust mad much difference Thanks
My H28.5 is getting on in years and I got to wondering about the motor mounts after reading a few weeks back about the tink tink someone heard and found to be a shot mount. So assuming that these rubber mounts vulcanize and may shrink over the years... are they just shot or does one just do the realignment. I checked Mack Boring ( a yanmar dealer) and they want $119 "each" for the (2)100 lbs and (2)75 lbs mounts on the 2GMF! sounds a bit rich for a flanged metal with rubber stopper. How many of you have "remounted" or just "adjusted" and has the readjust mad much difference Thanks
jtmccue, is your question based on an issue you're
having or just a curiosity? The Yanmar mounts are designed to dampen the shaking and low frequency vibration the engine produces at lower RPM. If you're having a problem it *could* be the mounts but a careful realignment might be in order. Remember too that vbrations can be produced by flaws in your prop, prop shaft or cutless bearing as well as mounts. With all that said, a carefull inspection of your (older) mounts should be made periodically. They can be damaged by frequent oil or fuel drenching so watch out for that. I have read that some report good results with other quality mounts that aren't as pricey. As an answer to another of your ?, I had a pretty bad vibration that was helped quite a bit by a couple of shaft/engine alignments. The first alignment showed a small improvement and the second brought it to where I thought it was good. Learning curve and stuff I guess.
having or just a curiosity? The Yanmar mounts are designed to dampen the shaking and low frequency vibration the engine produces at lower RPM. If you're having a problem it *could* be the mounts but a careful realignment might be in order. Remember too that vbrations can be produced by flaws in your prop, prop shaft or cutless bearing as well as mounts. With all that said, a carefull inspection of your (older) mounts should be made periodically. They can be damaged by frequent oil or fuel drenching so watch out for that. I have read that some report good results with other quality mounts that aren't as pricey. As an answer to another of your ?, I had a pretty bad vibration that was helped quite a bit by a couple of shaft/engine alignments. The first alignment showed a small improvement and the second brought it to where I thought it was good. Learning curve and stuff I guess.
mounts reprise
In the spring I'll do a haulout, inspect my cutlass, shine up my prop and mount the new Zincs(boy did Zincs get expensive since the last haul) now about $17ea. in NJ. The alignment will be done inwater cause I understand blocks and/or slings put different stress point on the hull. I saw the new style mounts in the photo section of this site- they look more like a car's "ball joint" than the inverted "w" mount I presently have and the "4" b/js type can be gotten for about $100. I agree that after the realign with a clean prop, shaft etc then I'll be able to know for sure. But it still appears that there's no history to determine when a m/m has gone beyond its functionality. Thanks
In the spring I'll do a haulout, inspect my cutlass, shine up my prop and mount the new Zincs(boy did Zincs get expensive since the last haul) now about $17ea. in NJ. The alignment will be done inwater cause I understand blocks and/or slings put different stress point on the hull. I saw the new style mounts in the photo section of this site- they look more like a car's "ball joint" than the inverted "w" mount I presently have and the "4" b/js type can be gotten for about $100. I agree that after the realign with a clean prop, shaft etc then I'll be able to know for sure. But it still appears that there's no history to determine when a m/m has gone beyond its functionality. Thanks
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