I'm having a problem with vibration while motoring my C-310. The engine seems to run very smoothly throughout it's entire RPM range but, at anything above 2000 RPM the entire stern of the boat has a rythmic vibration that increases in frequency as the RPM increases. The boat has had this problem since day one and it really started to get on my nerves while vacationing last week. In order to keep on schedule we had to motor for several hours in very light wind conditions. Has anyone else had this problem? Any thoughts on the origin of the vibration would be appreciated.
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Ed
Vibration
Bill: I have no 1st hand experience but I have heard of similar problems with others. You did not mention if you purchased the 310 new or not. I would recommend you start with the obvious and dive on the prop and shaft to see if all is well. Following that, you may want to have the shaft alignment checked. I understand that even a small variation in alignment can result in lots of vibration. In any case I would take it as a serious issue to track down. Good luck and let us know what you find.
Bill: I have no 1st hand experience but I have heard of similar problems with others. You did not mention if you purchased the 310 new or not. I would recommend you start with the obvious and dive on the prop and shaft to see if all is well. Following that, you may want to have the shaft alignment checked. I understand that even a small variation in alignment can result in lots of vibration. In any case I would take it as a serious issue to track down. Good luck and let us know what you find.
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Ron
Vibes
This can be a tough one to solve, as a boat has many harmonic resonance frequencies that can amplify any vibrations. Nevertheless, there are some basics regarding the drive chain to check out (more or less in order of problem likelihood). 1. Shaft alignment 2. Prop balance 3. Packing gland nut adjustment (too tight & there is no shaft lubrication) 4. Rudder post bearing play (the prop turbulance can really rattle a loose rudder) 5. Transmission 6. The engine internal shaft balance. Good luck. --Ron s/v Lady Jane
This can be a tough one to solve, as a boat has many harmonic resonance frequencies that can amplify any vibrations. Nevertheless, there are some basics regarding the drive chain to check out (more or less in order of problem likelihood). 1. Shaft alignment 2. Prop balance 3. Packing gland nut adjustment (too tight & there is no shaft lubrication) 4. Rudder post bearing play (the prop turbulance can really rattle a loose rudder) 5. Transmission 6. The engine internal shaft balance. Good luck. --Ron s/v Lady Jane
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Leo Brown
Vibes
I have a 30 mkIII w/ the 2 bladed prop w/ a "harmonic" sound which the mechanic calls normal and I call attrocious. For an explaination see www.westbynorth.com FAQ. I'm re-proping for next season. Smooth Sailing
I have a 30 mkIII w/ the 2 bladed prop w/ a "harmonic" sound which the mechanic calls normal and I call attrocious. For an explaination see www.westbynorth.com FAQ. I'm re-proping for next season. Smooth Sailing
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roger marshutz
vibration
I have a 310 and it runs smooth. Have a 3 bladed prop.. If the boat was bought from a dealer he should take care of it. It can be tough to find a good mechanic. Where are you located?
I have a 310 and it runs smooth. Have a 3 bladed prop.. If the boat was bought from a dealer he should take care of it. It can be tough to find a good mechanic. Where are you located?
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Bob
Go to the 310 owners site
Two sources of help with this. Check out Mainsheet Magazine August 2002 issue page T21 for a note on engine vibration. Also get plugged into the Catalina 310 owners list on Sailnet's website. Others have had this problem.
Two sources of help with this. Check out Mainsheet Magazine August 2002 issue page T21 for a note on engine vibration. Also get plugged into the Catalina 310 owners list on Sailnet's website. Others have had this problem.
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JC
Vibe
I have a 320 and get a similar vibration, especially when turning at 3/4 throttle. The vibration is causing the the throttle cable and/or exhaust hose to resonate against the hull. Also, the inspection cover boards under the aft cabin cushions resonate. My guess is that the 2 blade prop is the root cause, but until I replace it I'm going to wrap the cable and hose where they contact the hull and see if that eliminates most of the noise.
I have a 320 and get a similar vibration, especially when turning at 3/4 throttle. The vibration is causing the the throttle cable and/or exhaust hose to resonate against the hull. Also, the inspection cover boards under the aft cabin cushions resonate. My guess is that the 2 blade prop is the root cause, but until I replace it I'm going to wrap the cable and hose where they contact the hull and see if that eliminates most of the noise.
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Bill Babbitt
My dealer
The dealer I bought the boat from went out of business. Actually, the owner died and his son was not interested in running a marine dealership, so he sold off everything and is concentrating on the auto dealership. There is talk of one of the local boatyards picking up the Catalina line but nothing has happened yet. I'm located in Portland, Maine.
The dealer I bought the boat from went out of business. Actually, the owner died and his son was not interested in running a marine dealership, so he sold off everything and is concentrating on the auto dealership. There is talk of one of the local boatyards picking up the Catalina line but nothing has happened yet. I'm located in Portland, Maine.
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Ron
Vibes(2)
Try discussing the problem with Portland Yacht Services. Also, if you're there at PYS, drop in at the offices of Navigator Publications next door & see if one of their experts has any suggestions. --Ron
Try discussing the problem with Portland Yacht Services. Also, if you're there at PYS, drop in at the offices of Navigator Publications next door & see if one of their experts has any suggestions. --Ron
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Malcolm
Help Please
I have a 310 with exactly this problem (see previous posts in archive) and I have not been able to find a cure. I have already checked shaft alignment and have had the prop shaft replaced and a PSS shsft seal fitted, still have the original 2 blade prop which was supposedly balanced by the dealer. the problem is worst between 2100 and 2500 rpm afte 2500 she is smooth but this is a bit radical and not good for economy amongst other things. Checked the sailnet link but got lost. We are in Australia and to date have not seen more than one Mainsheet Magazine so a bit more on what is the article would help heaps. Thanks Malcolm
I have a 310 with exactly this problem (see previous posts in archive) and I have not been able to find a cure. I have already checked shaft alignment and have had the prop shaft replaced and a PSS shsft seal fitted, still have the original 2 blade prop which was supposedly balanced by the dealer. the problem is worst between 2100 and 2500 rpm afte 2500 she is smooth but this is a bit radical and not good for economy amongst other things. Checked the sailnet link but got lost. We are in Australia and to date have not seen more than one Mainsheet Magazine so a bit more on what is the article would help heaps. Thanks Malcolm
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Matt
Engine RPM
Malcolm, The 25MXP Universal engine has a maximum rated rpm of around 3300rpm. Running your engine at 2500rpm is not only good for it, but is what is recommended by the manufacturer. If you are getting less vibration at 2500rpm, then this should be your cruising rpm until you replace your 2 blade prop with a 3 blade prop. You can then probably get away with 2000-2200rpm with less vibration and a little better fuel consumption. But it is still a good idea to run your engine at the higher rpms often, as this will reduce the carbon build-up and other internal engine problems associated with running at less than 70-80% of the maximum rpm on a diesel engine. At 2400rpm, your fuel consumption is probably only 0.5gph, going up to maybe 0.8gph at 2600rpm, so with a 28 gallon tank, worrying about fuel consumption should be the least of your worries. I would worry more about the damage that the vibration is causing to hoses and mounts trying to motor at a lower rpm with excessive vibration. I have hull #127, and if I have somewhere to go, I generally set the engine speed to 2500rpm and sit back and relax. I move along at 5.5 knots and enjoy the scenery. Matt
Malcolm, The 25MXP Universal engine has a maximum rated rpm of around 3300rpm. Running your engine at 2500rpm is not only good for it, but is what is recommended by the manufacturer. If you are getting less vibration at 2500rpm, then this should be your cruising rpm until you replace your 2 blade prop with a 3 blade prop. You can then probably get away with 2000-2200rpm with less vibration and a little better fuel consumption. But it is still a good idea to run your engine at the higher rpms often, as this will reduce the carbon build-up and other internal engine problems associated with running at less than 70-80% of the maximum rpm on a diesel engine. At 2400rpm, your fuel consumption is probably only 0.5gph, going up to maybe 0.8gph at 2600rpm, so with a 28 gallon tank, worrying about fuel consumption should be the least of your worries. I would worry more about the damage that the vibration is causing to hoses and mounts trying to motor at a lower rpm with excessive vibration. I have hull #127, and if I have somewhere to go, I generally set the engine speed to 2500rpm and sit back and relax. I move along at 5.5 knots and enjoy the scenery. Matt
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Bill Babbitt
3 blade prop? / time for a solution.
Matt; Can I Assume you have a three blaed prop? I brought up the engine vibration problem on the Sailnet C-310 list and it generated quite a lot of response. It seems that many have it but some don't. The two blade prop has more vibration problems than the three. Some boats with the three blade prop also have the problem but to a lesser degree. Perhaps it's time for us C-310 owners with a vibration problem to band together and work with Catalina to find a root cause and solution for what seems to be a common problem. Bill Babbitt C-310 #153
Matt; Can I Assume you have a three blaed prop? I brought up the engine vibration problem on the Sailnet C-310 list and it generated quite a lot of response. It seems that many have it but some don't. The two blade prop has more vibration problems than the three. Some boats with the three blade prop also have the problem but to a lesser degree. Perhaps it's time for us C-310 owners with a vibration problem to band together and work with Catalina to find a root cause and solution for what seems to be a common problem. Bill Babbitt C-310 #153
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Dr. Kevin Quade
Vibration problem
My 310 vibrates profusely under 930rpm. If I increase the idle above this rpm it runs pretty smoothly. At the rpm set by the factory, the engine ran roughly enough to vibrate the transmision dipstick out of the trans. This caused loss of trans oil into the boat. What a mess! The engine ran roughly enough in the first 10 hours to almost wear through the side of a water hose also. I have friends with one cylinder diesels that run smoother than this engine. We are crazy about our 310, she's a great boat, but the engine vibration really bothers me.
My 310 vibrates profusely under 930rpm. If I increase the idle above this rpm it runs pretty smoothly. At the rpm set by the factory, the engine ran roughly enough to vibrate the transmision dipstick out of the trans. This caused loss of trans oil into the boat. What a mess! The engine ran roughly enough in the first 10 hours to almost wear through the side of a water hose also. I have friends with one cylinder diesels that run smoother than this engine. We are crazy about our 310, she's a great boat, but the engine vibration really bothers me.
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roger marshutz
vibes
I would find a good mechanic and see what he has to say. MY 310 no, 164 runs fine. Slightly vibrates at maybe at the dealer settings so I just increass the rpm a little. I have a 3 bladed prop.
I would find a good mechanic and see what he has to say. MY 310 no, 164 runs fine. Slightly vibrates at maybe at the dealer settings so I just increass the rpm a little. I have a 3 bladed prop.
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Malcolm
thanks Matt
Thanks for the advice I will run at 2500 -2600 and get over it not worried about fuel consumption only possible wear and if higher rpms are ok then thats good. I can onlt get about 26 - 2700 rpm even in neutral this is why I was avoiding higher engine speeds. I'll now look into that problem if others are getting 3000 plus. Malcolm
Thanks for the advice I will run at 2500 -2600 and get over it not worried about fuel consumption only possible wear and if higher rpms are ok then thats good. I can onlt get about 26 - 2700 rpm even in neutral this is why I was avoiding higher engine speeds. I'll now look into that problem if others are getting 3000 plus. Malcolm
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Matt
Good vibrations?
I think that there is quite a bit of confusion regarding idle speed for the M25XPB and the inherent vibration that this engine exhibits. The literature that came with the boat recomends 1000-1100 RPM for idle. In my experience, anything less than 1100 RPM causes excessive vibration. It may be that some dealers were not paying attention to this recomendation and set the idle too low at commisioning on some boats. I have read quite a few posts that talk of 900 RPM or lower, with much dismay about the vibration. Time to turn the idle up in those boats to 1100 and stop the shaking. Also, it seems that those of us with the 3-blade prop are much happier, with much smoother running and less vibration under power. This only makes sense, as the amount of cavitation of a 2-blade prop is extreme. I actually went to a 4-blade prop on my old ski boat for the same reasons, smoother ride with less vibration. I went back and looked up the max rpm for the M25XPB engine, which was 3000 rpm (I was thinking it was 3200) so this would give an 80% cruise rpm of 2400 RPM. I generally run at about 2500 RPM, but my engine will rev to 3200 RPM, so it could be a difference in tachometer calibration. Catalina should do a better job of informing their dealers about the idle speed for this engine, so that they correctly setup the boat during commisioning. Also, if you take a section of 3/4" hose and split it down the middle, it makes a great chafe guard for where the water and fuel hoses go under the wall between the engine compartment and the stern bed. Without some type of protection at this point, you could quickly cut through these hoses due to the engine vibration.
I think that there is quite a bit of confusion regarding idle speed for the M25XPB and the inherent vibration that this engine exhibits. The literature that came with the boat recomends 1000-1100 RPM for idle. In my experience, anything less than 1100 RPM causes excessive vibration. It may be that some dealers were not paying attention to this recomendation and set the idle too low at commisioning on some boats. I have read quite a few posts that talk of 900 RPM or lower, with much dismay about the vibration. Time to turn the idle up in those boats to 1100 and stop the shaking. Also, it seems that those of us with the 3-blade prop are much happier, with much smoother running and less vibration under power. This only makes sense, as the amount of cavitation of a 2-blade prop is extreme. I actually went to a 4-blade prop on my old ski boat for the same reasons, smoother ride with less vibration. I went back and looked up the max rpm for the M25XPB engine, which was 3000 rpm (I was thinking it was 3200) so this would give an 80% cruise rpm of 2400 RPM. I generally run at about 2500 RPM, but my engine will rev to 3200 RPM, so it could be a difference in tachometer calibration. Catalina should do a better job of informing their dealers about the idle speed for this engine, so that they correctly setup the boat during commisioning. Also, if you take a section of 3/4" hose and split it down the middle, it makes a great chafe guard for where the water and fuel hoses go under the wall between the engine compartment and the stern bed. Without some type of protection at this point, you could quickly cut through these hoses due to the engine vibration.
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