I just had a survey done on a 1977 Catalina 30'. It had a rebuild on it's Yanmar 12hp Diesel in 1999. The engine, according to the surveyor, is in good shape. I was a little taken back by how underpowered it felt. Does anyone else have a 12hp Diesel that is pushing their 30 footer? What kind of speeds should I expect? It sure seemed to struggle quite a bit (3-4 knots max). Is this typical? Could it be an incorrect prop size? It didn't seem to pushing too many rpm's... Any help or suggestions would be greatly appreciated... Thanks, Gary
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Matt
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Steve W.
I have read a lot of owner comments about C30's...
being underpowered with the 11hp Universal diesel. I guess you have to decide how much slow motoring you are patient enough to put up with. Good luck.
being underpowered with the 11hp Universal diesel. I guess you have to decide how much slow motoring you are patient enough to put up with. Good luck.
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Gary
Universal 11 hp
I have a 11 hp in my 77 Catalina and we have a 2 blade folding prop. We can get about 6 kts. most of the time. When motoring into 25 kts of wind and chop we slow down to about 5. More power would be nicw but I would not walk away from a good deal just because of a 12 hp. engine. I would check out the prop size, could have a lot to do with it.
I have a 11 hp in my 77 Catalina and we have a 2 blade folding prop. We can get about 6 kts. most of the time. When motoring into 25 kts of wind and chop we slow down to about 5. More power would be nicw but I would not walk away from a good deal just because of a 12 hp. engine. I would check out the prop size, could have a lot to do with it.
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Gary
77 Catalina
Gary You can reach me at this web site. I can give you some other hints on what to look for on this year boat. I have had mine for 14 years now. Gary http://members.aol.com/ahycrace
Gary You can reach me at this web site. I can give you some other hints on what to look for on this year boat. I have had mine for 14 years now. Gary http://members.aol.com/ahycrace
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Gary C
Thanks!
Thank you all for your input! I went ahead and purchased this boat, and have been enjoying every minute of it. There is a lot of growth on the prop and shaft...could this be part of the problem?
Thank you all for your input! I went ahead and purchased this boat, and have been enjoying every minute of it. There is a lot of growth on the prop and shaft...could this be part of the problem?
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Tony O.
Hull speed
Another consideration is your maximum hull speed. On the C-30 it happens to be 6.7 knts. When you exceed that speed you are pushing more water than the hull is designed to move efficently through. In this scenario, you put undue stress on your boat's motor no matter how many Horses you have. Ask yourself what you need the motor for. What kind of boating do you do more of, motoring or sailing? A sailboat is meant to sail a motorboat is mean to motor. There is a place where the two kinds of boats meet on the continum; Its called a motor/sailer.
Another consideration is your maximum hull speed. On the C-30 it happens to be 6.7 knts. When you exceed that speed you are pushing more water than the hull is designed to move efficently through. In this scenario, you put undue stress on your boat's motor no matter how many Horses you have. Ask yourself what you need the motor for. What kind of boating do you do more of, motoring or sailing? A sailboat is meant to sail a motorboat is mean to motor. There is a place where the two kinds of boats meet on the continum; Its called a motor/sailer.
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Paul
Growth on the bottom will slow you down...
...especially if your HP is marginal to begin with. My Catalina 27 is powered by an 8 HP Honda outboard and when I first tested it, it cruised at about 4 kts and maxed out at 5. However it had not been out of the water in years and had not moved at all in over 6 months. I hauled it out, cleaned and painted the bottom and now I cruise at 5.5 kts at 2/3 throttle and max out over 6 kts. Paul 1974 Catalina 27 Vancouver, BC
...especially if your HP is marginal to begin with. My Catalina 27 is powered by an 8 HP Honda outboard and when I first tested it, it cruised at about 4 kts and maxed out at 5. However it had not been out of the water in years and had not moved at all in over 6 months. I hauled it out, cleaned and painted the bottom and now I cruise at 5.5 kts at 2/3 throttle and max out over 6 kts. Paul 1974 Catalina 27 Vancouver, BC
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Tom
GPS or knotmeter?
If your speed is based on the knotmeter readings, you may want to compare them with a GPS. You will have to take any current effect into account if you are in salt water. Knotmeter readings are sometimes not the most accurate gage of boatspeed. The 11 hp Universal in my C30 allows the boat to travel at 5.5-6 kts through the water, with no wind/chop.
If your speed is based on the knotmeter readings, you may want to compare them with a GPS. You will have to take any current effect into account if you are in salt water. Knotmeter readings are sometimes not the most accurate gage of boatspeed. The 11 hp Universal in my C30 allows the boat to travel at 5.5-6 kts through the water, with no wind/chop.
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