When motor sailing, at engine RPM’s above 2900 and continuously up to 3700 RPM there is a bad vibration that you can feel in your legs at the helm. With no load, transmission in neutral, engine RPM from 1000 to 3500 runs smooth as silk, NO vibration. With the engine’ drive shaft and dripless coupling exposed I held a finger tip on the drive shaft and with engine RPM from 1000 to 2900 the shaft ran true, no vibration. As soon as the RPM exceeds 2900 the shaft starts to whip and my finger tip bounces off the surface. The amplitude of the vibration seems to increase as the RPM increased to 3500 max. The dripless coupling vibration was very noticeable by eye. The engine and transmission were both vibrating but appeared to be not as severe as the shaft vibration. To date my dealer inspected the cutlass bearing and had the propeller balanced and reinstalled both were OK. Now the exerts, Yanmar, Hunter and my dealer think that possibly the shaft is out of alignment or it is bent or the 2 bladed prop needs to be a 3 bladed prop. Are there any other 410 owners with a similar problem that have found a solution in less than a year of playing?
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Howard Kornack
Engine vibration
Had the exact same problem on my 380. The fix was two-fold. First the dealer re-aligned the engine which removed about 30% of the vibration. The major improvement however, came from insatlling a 3-blade prop (keep the old one as a spare for emergencies). The engine is now smooth as silk at all rpm's
Had the exact same problem on my 380. The fix was two-fold. First the dealer re-aligned the engine which removed about 30% of the vibration. The major improvement however, came from insatlling a 3-blade prop (keep the old one as a spare for emergencies). The engine is now smooth as silk at all rpm's
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Rafael Perez
Yes, the same.
I have exactly the same problem, but mine starts shaking at about 2600 RPM. A technician verified the shaft alignment and it was OK. I'm waiting for the end of the summer season to take the boat out and see if we can find a problem: bent shaft (I haven´t fouled the prop or had any other accident) or a worn cutlass bearing (shouldn´t be because the vibration is there from the very first day and now the engine is only 160 hours, the boat is one year old with only a bit more than 1000 nm) Two technicians bet it is going to be the fault of a wrong sized propeller. A three bladed prop would be a more suitable option for a boat like the H410. Regards, Rafael Perez H410 Marina Clara rps00002@teleline.es
I have exactly the same problem, but mine starts shaking at about 2600 RPM. A technician verified the shaft alignment and it was OK. I'm waiting for the end of the summer season to take the boat out and see if we can find a problem: bent shaft (I haven´t fouled the prop or had any other accident) or a worn cutlass bearing (shouldn´t be because the vibration is there from the very first day and now the engine is only 160 hours, the boat is one year old with only a bit more than 1000 nm) Two technicians bet it is going to be the fault of a wrong sized propeller. A three bladed prop would be a more suitable option for a boat like the H410. Regards, Rafael Perez H410 Marina Clara rps00002@teleline.es
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Bryce Grefe
410 vibration
Had the same problem last year. Swapped my factory prop for a three blade autoprop and ended the problem. I've sinced had the factory two blade balanced and trued, (apparently it was quite bad according to the prop service) and will keep as a backup. Bryce S/V Spellbinder
Had the same problem last year. Swapped my factory prop for a three blade autoprop and ended the problem. I've sinced had the factory two blade balanced and trued, (apparently it was quite bad according to the prop service) and will keep as a backup. Bryce S/V Spellbinder
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Steve Feinsilver
engine vibration
I have a new 410, and it seems to be quite smooth, but I never run it at nearly the RPMs you mention. The boat motors nicely at about 2800 rpm, and I always thought this was a good engine speed (boat speed about 7 kts or better). Is it a good idea to run the engine at 3000 plus? I am embarrassed to sat that I have never seen my prop, I don't even know whether it is a 2 or 3 blade.
I have a new 410, and it seems to be quite smooth, but I never run it at nearly the RPMs you mention. The boat motors nicely at about 2800 rpm, and I always thought this was a good engine speed (boat speed about 7 kts or better). Is it a good idea to run the engine at 3000 plus? I am embarrassed to sat that I have never seen my prop, I don't even know whether it is a 2 or 3 blade.
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Chris Webb
410 engine vibration
Steve, I have 410 #153 and have had no trouble with engine vibration either from the standard 2 blade factory prop or from the 3 bladed Autoprop I changed to. Sounds to me like either an engine alignment for shaft problem. I'd continue looking there. Best of luck. Chris Webb s/v Grand Cru II
Steve, I have 410 #153 and have had no trouble with engine vibration either from the standard 2 blade factory prop or from the 3 bladed Autoprop I changed to. Sounds to me like either an engine alignment for shaft problem. I'd continue looking there. Best of luck. Chris Webb s/v Grand Cru II
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Steve Moss
High Engine RPM
I am surprised at the high rpms people are running there engines at. In my 37.5, I would not think of going over 2600rpm at 6.5kts.
I am surprised at the high rpms people are running there engines at. In my 37.5, I would not think of going over 2600rpm at 6.5kts.
Steve Moss
Steve: I think if you check out the Yanmar manual you will find that the optimum operating range is 70-80% of the max rated RPMS's. This means that an engine that is rated at 3600rpm's should be run in the 2500-2900 rpm range. Their ratings are suppose to provide optimum cooling and economy (according to their performance charts). Not all of the Yanmars are rated at 3600, so this needs to be taken into account. In your case you do not need to worry about corrosion (fresh water) but do need to worry about coking of the mixing elbow. This is one of the major causes of overheating in the Yanmar engines. The elbow must be clear so the raw water and the exhaust can mix. If the elbow clogs the exhaust cannot escape the engine (back pressure) and the raw water cannot flow (overheating). Remember that these are basically medium speed diesels. Many of the marine deisels only need to be run in the 1800-2100 rpms range. Just a different technology. I have been assured that a properly maintained Yanmar can last for 12k-15k hours.
Steve: I think if you check out the Yanmar manual you will find that the optimum operating range is 70-80% of the max rated RPMS's. This means that an engine that is rated at 3600rpm's should be run in the 2500-2900 rpm range. Their ratings are suppose to provide optimum cooling and economy (according to their performance charts). Not all of the Yanmars are rated at 3600, so this needs to be taken into account. In your case you do not need to worry about corrosion (fresh water) but do need to worry about coking of the mixing elbow. This is one of the major causes of overheating in the Yanmar engines. The elbow must be clear so the raw water and the exhaust can mix. If the elbow clogs the exhaust cannot escape the engine (back pressure) and the raw water cannot flow (overheating). Remember that these are basically medium speed diesels. Many of the marine deisels only need to be run in the 1800-2100 rpms range. Just a different technology. I have been assured that a properly maintained Yanmar can last for 12k-15k hours.
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