I BOUGHT A 1978 S2 9.2 SAILBOAT THIS FALL AND WANT TO KNOW HOW FAST IT WILL GO UNDER POWER WITH THE YAMAR 9 HP ENGINE IT CAME WITH. I AM THINKING I MAY WANT TO REPOWER IT AND WANT TO KNOW WHAT SIZE ENGINE TO USE. THANK YOU, DION.
- Status
motoring
i have a 17H beta marine ...i get about 6 knots ...with a clean bottom and prop..it is a heavy boat...theoretical hull speed is only around 7 1/2 knots
i have a 17H beta marine ...i get about 6 knots ...with a clean bottom and prop..it is a heavy boat...theoretical hull speed is only around 7 1/2 knots
9.2A Re Engine Boat Speed
I removed 1976 Yanmar YSE12 12hp that leaked and smoked and installed a 1978 Yanmar 3GMD 20hp that was removed from a 38' sailboat. The owner wanted to install a 40hp engine, but his 3GMD was in good condition. I had to raise the engine mounts about 2 1/2" and move the entry stairs box forward about 5 1/2", I also installed a 3 blade prop. I now get up to 7.4kt of boat speed on my GPS at full power on flat water, no wind. Fuel comsumption has increased, I previously fueled every 8-10 months, now about every 6 months. I recommend the 20hp engine size, but the 17hp Beta was one that I looked at and would do fine. The Yanmar just came up at the right time and the price was right.
I removed 1976 Yanmar YSE12 12hp that leaked and smoked and installed a 1978 Yanmar 3GMD 20hp that was removed from a 38' sailboat. The owner wanted to install a 40hp engine, but his 3GMD was in good condition. I had to raise the engine mounts about 2 1/2" and move the entry stairs box forward about 5 1/2", I also installed a 3 blade prop. I now get up to 7.4kt of boat speed on my GPS at full power on flat water, no wind. Fuel comsumption has increased, I previously fueled every 8-10 months, now about every 6 months. I recommend the 20hp engine size, but the 17hp Beta was one that I looked at and would do fine. The Yanmar just came up at the right time and the price was right.
Over 6 knots with a Yanmar 2GM
My 9.2 with a clean bottom and a folding prop will do over 6 knots with it's 2GM at full throttle. Since the speed limit is 5 knots in the congested areas where I motor to get to sail, the engine only has to run at 75 - 80% throttle most of the time.
My 9.2 with a clean bottom and a folding prop will do over 6 knots with it's 2GM at full throttle. Since the speed limit is 5 knots in the congested areas where I motor to get to sail, the engine only has to run at 75 - 80% throttle most of the time.
S2 9.2 OEM engine
My 1978 has the same engine as yours. I constantly get 6.4-6.6 kts in/out of harbor and on days of no wind when motoring is required. IMHO, unless, something is horribly wrong with your engine, swapping it out just because you can, doesn't seem to economical to me. Besides, as stated in the other posts, your fuel use increases, you're only gaining about 1-2 kts of thrust. We don't have sailboats for that type of motoring speed, do we? Plus, you'll probably miss a month of sailing this season (with a good mechanic who knows and has all he needs to accomplish the task quickly) since you'll remain in dry dock while this occurs.
My 1978 has the same engine as yours. I constantly get 6.4-6.6 kts in/out of harbor and on days of no wind when motoring is required. IMHO, unless, something is horribly wrong with your engine, swapping it out just because you can, doesn't seem to economical to me. Besides, as stated in the other posts, your fuel use increases, you're only gaining about 1-2 kts of thrust. We don't have sailboats for that type of motoring speed, do we? Plus, you'll probably miss a month of sailing this season (with a good mechanic who knows and has all he needs to accomplish the task quickly) since you'll remain in dry dock while this occurs.
It depends...
You are the judge. If you are consistently having to change your plans due to the fact that you can't motor against strong currents / tides in your area and you plan to keep the boat for a while then repowering is a sound investment. A 9hp is pretty darn marginal. I took a survey a few weeks ago...asked folks what choice they would make all other things being equal...a 1 cyl 12 hp or a 2 cyl 15 hp...if the 1 cyl was ~$3000 cheaper and everyone said take the 2cyl. I am buying the 1981 S2 9.2A with the 15hp 2 cyl for 20k. I wouldn't have paid 15K for the 1 cyl 12 hp (more like 12K would have been preferred), partially because the need to repower is more likely. The few repowered boats I saw on the market...very few...were at a premium price to the market at about $23-25K. So, long story short, if you spend $12-15K for a repower you might get $10-12K back, especially as the 9hp will be a real handicap at selling time. Just my opinion of course, which is based upon my recent review of all the boats available at the moment from DC to MI to ME. Also worth noting is that prices in MI seems to be about 10% higher than elsewhere, likely due to their popularity near their birthplace. Were I to repower, I'd probably go with the smallest 3 cylinder diesel (more cylinders = smoother operation) I could find, although the 3YM20 (21hp) and 3YM30 (29hp) are about equal in weight (+5lbs for the latter) I'd probably stick to yanmar if the price is competative as they have the best reputation as far as I can tell, which will was a consideration for me when purchasing. Barring yanmar, I'd probably look for who has the best local dealer in your area. Good luck, Bob
You are the judge. If you are consistently having to change your plans due to the fact that you can't motor against strong currents / tides in your area and you plan to keep the boat for a while then repowering is a sound investment. A 9hp is pretty darn marginal. I took a survey a few weeks ago...asked folks what choice they would make all other things being equal...a 1 cyl 12 hp or a 2 cyl 15 hp...if the 1 cyl was ~$3000 cheaper and everyone said take the 2cyl. I am buying the 1981 S2 9.2A with the 15hp 2 cyl for 20k. I wouldn't have paid 15K for the 1 cyl 12 hp (more like 12K would have been preferred), partially because the need to repower is more likely. The few repowered boats I saw on the market...very few...were at a premium price to the market at about $23-25K. So, long story short, if you spend $12-15K for a repower you might get $10-12K back, especially as the 9hp will be a real handicap at selling time. Just my opinion of course, which is based upon my recent review of all the boats available at the moment from DC to MI to ME. Also worth noting is that prices in MI seems to be about 10% higher than elsewhere, likely due to their popularity near their birthplace. Were I to repower, I'd probably go with the smallest 3 cylinder diesel (more cylinders = smoother operation) I could find, although the 3YM20 (21hp) and 3YM30 (29hp) are about equal in weight (+5lbs for the latter) I'd probably stick to yanmar if the price is competative as they have the best reputation as far as I can tell, which will was a consideration for me when purchasing. Barring yanmar, I'd probably look for who has the best local dealer in your area. Good luck, Bob
- Status