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Outboard recommendations for a San Juan 21
I need to buy an outboard for my San Juan 21 and not quite sure about how
big to go. I would like a 4 stroke and I am thinking that about 5 HP would be a good size. Any comments about the different brands would be appreciated. Also, do I really need a "long shaft" motor. With the motor mount currently on the boat, it seems to me that any motor would easily bury the prop. Regards, Bruce |
Outboard recommendations for a San Juan 21
Hi Bruce
A long shaft is definitely recommended. In an emergency (read storm) the wave action would have your prop more above than below the waterline. So not thrust. FWIW -- c ya Wim www.cruising.ca/thousand/f-index.html "Bruce" wrote in message ... : I need to buy an outboard for my San Juan 21 and not quite sure about how : big to go. I would like a 4 stroke and I am thinking that about 5 HP would : be a good size. Any comments about the different brands would be : appreciated. : Also, do I really need a "long shaft" motor. With the motor mount currently : on the boat, it seems to me that any motor would easily bury the prop. : : Regards, : Bruce : : |
Outboard recommendations for a San Juan 21
A long shaft Yamaha or Honda would be a good choice. It will run you about
$300 to $800 more than a Mercury or OMC (Johnson / Evinrude) but these are bullet-proof motors. The Yamaha's are little rare in some parts of the country but the Honda's are fairly available. If you are going out of country (like Mexico) you may want to consider a Mercury. Note too that the Nissan, Suzuki and Mercury (Mariner) small bore motors are actually made by Tohatsu. The size you want is about right for that boat. Anything from 4 to 8 hp should do the job... more costs more so think about your horsepower with the idea that it may be used for hours at a time if you have no wind and are impatient or if you have a lot of wind and need to handle the boat against it. Best; Chris "Bruce" wrote in message ... I need to buy an outboard for my San Juan 21 and not quite sure about how big to go. I would like a 4 stroke and I am thinking that about 5 HP would be a good size. Any comments about the different brands would be appreciated. Also, do I really need a "long shaft" motor. With the motor mount currently on the boat, it seems to me that any motor would easily bury the prop. Regards, Bruce |
Outboard recommendations for a San Juan 21
"Chris Edmonson" wrote...
A long shaft Yamaha or Honda would be a good choice. It will run you about $300 to $800 more than a Mercury or OMC (Johnson / Evinrude) but these are bullet-proof motors. The Yamaha's are little rare in some parts of the country but the Honda's are fairly available. If you are going out of country (like Mexico) you may want to consider a Mercury. Note too that the Nissan, Suzuki and Mercury (Mariner) small bore motors are actually made by Tohatsu. The size you want is about right for that boat. Anything from 4 to 8 hp should do the job... Remember that the 8 HP motor is the same as the 10, except for max RPM and HP rating (about 105 lb for the Yamaha 4-stroke, long-shaft, 'sailboat special', IIRC). Therefore, it is MUCH heavier than the 5 HP. For the small boat, lighter is better! I had both Honda and Yamaha 10s on my San Juan 7.7. Either one was overkill in terms of HP. The Honda was lighter, but the Yamaha had a better feature set with the starter and alternator. I now have a Honda 4-stroke 2 on my SeaPearl 21 (much lighter and cleaner than the San Juan 21, though). A 4 or 5 HP 4-stroke should be plenty for the San Juan. A long shaft is good for sailboats, mainly because of the pitching action in waves that will lift a short shaft out of the water. You want to have the prop lower than you normally would for a transom mount on a powerboat, so it will stay in the water when pitching. |
Outboard recommendations for a San Juan 21
Hi Bruce,
I'm surprised that nobody in their replies to you has brought up the subject of gear ratio's. Unless things have changed in the past year or so, I found it was difficult to find a motor with a high gear ratio(close to 3.0), as opposed to the common 'egg beater' offerings (closer to 2.0 or less). Most sailboats are heavy displacement vessels (except for some catamarans, etc.), and will not come out of the water to plane. This translates into a requirement for a 'pusher' type motor, where the propellor turns slower for any given engine speed, but produces more torque, or push. I almost bought the Honda two years ago, but when I discovered that it's gear ratio was close to 2.0, switched my decision to the Yamaha 4 stroke 'high thrust' model with a gear ratio of 2.92. Some people may claim that their Honda's work fine on their boats, but I would guess that if they got caught in a strong on coming sea, they would have trouble pointing their boat into the wind. The only other engine I considered was a Mercury 4-stroke, but it weighed about 20 pounds more than the equivalent Yamaha, but did have a decent gear ratio. The best pusher I ever owned was a British Seagull, with a gear ratio of almost 4.0. That engine was shown in photos push huge barges around (only 6 hp). I have the 9.9 hp Yamaha on my 22 foot sailboat, which weighs about 2 tons unloaded. I could have gone with their 8.0 hp high thrust engine, but for some strange reason, it actually weighed a few pounds more than the 9.9 and I felt the extra horsepower would give better performance. I don't know why there are not more offerings of high gear ratio engines. When I bought my Chrysler 'Sailor' model over a decade ago, there was a wider selection of these types. My only regret is that the Yamaha is not lighter, as I can no longer heft it's 99 pounds over the transom into the boat, as I could with my previous engines. Although 4-strokes are inherently heavier than their 2-stroke counterparts, eventually they will be able to get the weights down to more reasonable levels. Sherwin Dubren Bruce wrote: I need to buy an outboard for my San Juan 21 and not quite sure about how big to go. I would like a 4 stroke and I am thinking that about 5 HP would be a good size. Any comments about the different brands would be appreciated. Also, do I really need a "long shaft" motor. With the motor mount currently on the boat, it seems to me that any motor would easily bury the prop. Regards, Bruce |
Outboard recommendations for a San Juan 21
All good points being made here. If the wieght maximum you have in mind is
clear to you then go with a smaller four stroke. I have found it difficult to move much more than fifty or sixty pounds of bulky motor around so would tend to go with a smaller motor than a lot of folks might choose. The other thing is that the four strokes make power at a lower RPM so may be best on fuel economy over the long run. The gear ratio is perhaps not as large an issue as it was when almost all of the motors were two strokes that needed the higher RPM's to get you going. The propeller's pitch can give you some of the pushing power that the old gear ratio change would give. If you don't have enough umph move down a couple of inches in pitch and gain power earlier in the curve. The four strokes definitely handle this change very well. Best; Chris "Bruce" wrote in message ... I need to buy an outboard for my San Juan 21 and not quite sure about how big to go. I would like a 4 stroke and I am thinking that about 5 HP would be a good size. Any comments about the different brands would be appreciated. Also, do I really need a "long shaft" motor. With the motor mount currently on the boat, it seems to me that any motor would easily bury the prop. Regards, Bruce |
Outboard recommendations for a San Juan 21
On Wed, 22 Oct 2003 19:56:06 -0400, "Bruce"
wrote: I need to buy an outboard for my San Juan 21 and not quite sure about how big to go. How are you going to use it? If you are only going to use it for getting out of and into the slip, I'm wondering if an electric trolling motor would suit your needs. It's lighter, less expensive, and much quieter than any sort of fuel motor. |
Outboard recommendations for a San Juan 21
Hi Chris,
Your point about the 4-strokes developing power (or torque) at lower rpm's than 2-strokes is correct, but I'm not sure that leaves the gear ratio's out of the picture entirely. First of all, why would Yamaha and Mercury go to higher gear ratio's on their 'high thrust' engines, if it would be simpler to just change the propellor pitch to achieve the same result? Secondly, I would be a little nervous about experimenting with a propellor's pitch to match it optimally to the engine. The bottom line is will a 4-stroke engine with a low gear ratio and a compensating pitch propellor run as well as a 4-stroke with a higher gear ratio engine with it's appropriate propellor (I don't think so). Actually, both the higher gear ratio and the propellor can each contribute to the higher thrust. However, given a choice, I would go with the higher gear ratio which would allow me to get even more thrust by decreasing the propellor pitch. With the lower gear ratio engines, I can only lower the pitch of the propellor which has obvious limits as to how much this can be done. Sherwin Dubren Chris Edmonson wrote: All good points being made here. If the wieght maximum you have in mind is clear to you then go with a smaller four stroke. I have found it difficult to move much more than fifty or sixty pounds of bulky motor around so would tend to go with a smaller motor than a lot of folks might choose. The other thing is that the four strokes make power at a lower RPM so may be best on fuel economy over the long run. The gear ratio is perhaps not as large an issue as it was when almost all of the motors were two strokes that needed the higher RPM's to get you going. The propeller's pitch can give you some of the pushing power that the old gear ratio change would give. If you don't have enough umph move down a couple of inches in pitch and gain power earlier in the curve. The four strokes definitely handle this change very well. Best; Chris "Bruce" wrote in message ... I need to buy an outboard for my San Juan 21 and not quite sure about how big to go. I would like a 4 stroke and I am thinking that about 5 HP would be a good size. Any comments about the different brands would be appreciated. Also, do I really need a "long shaft" motor. With the motor mount currently on the boat, it seems to me that any motor would easily bury the prop. Regards, Bruce |
Outboard recommendations for a San Juan 21
Sherwin;
True enough that gear ratio is of import but I think in the dollar range I have seen people willing to spend a $150 propeller change will get more for the expense than the $700 to $1500 sometimes charged for gear change. The retail marine motor business is spotty at best. Often someone looking for a particular motor will find that particular motor difficult to obtain. I have even had people look into changing a short shaft motor into a long shaft motor along with a gear change... just not cost effective. I guess I was thinking more of someone wanting to correct a situation with an existing motor than getting a new one. Motors are set up for the different kinds of jobs they do. A work boat will typically have the "high thrust" version whereas a sport fishing boat often goes for speed / troll trade-offs. A sailboat that cannot plane does not need a high pitch prop (equates to higher end speed in a planing hull). The rule of thumb is that for every inch of pitch change you will increase or decrease your max rpm's by 150 tp 200 rpm (a fact that is written on the Mercury propeller box). For fuel economy you might choose a lower pitch that will make power at a lower rpm... in a way this IS a gear change. On my own sailboats I have gotten hull speed long before I ever get to max thrust of the motor. It has allowed a smaller motor to be used and saved on the expense and wieght of the larger motor and the fuel savings on a long use of the motor. This last is relatively unimportant because in a season's use I can count the tanks used on one hand! Because the high thrust option is needed to extend even further the range of useful power generated by the engine it is reasonable to make a motor with a MUCH higher gear ratio... so in terms of designing a workboat or sailboat motor it is understandable that the gear ratios are offered. It is just that they are not readily available everywhere. There are charts at almost all marine motor dealers that match pitch to a variety of motors so there isn't really much experimenting to do to get the power you are seeking. Overall I have to agree with pretty much everything you say BUT in terms of expense and availability I would look at my motor with the idea that unless I were replacing the whole thing I would opt for a pitch change before I would get hung up on getting a motor that may not be obtainable at the moment. Your points are very well taken though and if you can find the gear ratio option it is an easy cure for the thrust question. Best; Chris "Sherwin Dubren" wrote in message ... Hi Chris, Your point about the 4-strokes developing power (or torque) at lower rpm's than 2-strokes is correct, but I'm not sure that leaves the gear ratio's out of the picture entirely. First of all, why would Yamaha and Mercury go to higher gear ratio's on their 'high thrust' engines, if it would be simpler to just change the propellor pitch to achieve the same result? Secondly, I would be a little nervous about experimenting with a propellor's pitch to match it optimally to the engine. The bottom line is will a 4-stroke engine with a low gear ratio and a compensating pitch propellor run as well as a 4-stroke with a higher gear ratio engine with it's appropriate propellor (I don't think so). Actually, both the higher gear ratio and the propellor can each contribute to the higher thrust. However, given a choice, I would go with the higher gear ratio which would allow me to get even more thrust by decreasing the propellor pitch. With the lower gear ratio engines, I can only lower the pitch of the propellor which has obvious limits as to how much this can be done. Sherwin Dubren Chris Edmonson wrote: All good points being made here. If the wieght maximum you have in mind is clear to you then go with a smaller four stroke. I have found it difficult to move much more than fifty or sixty pounds of bulky motor around so would tend to go with a smaller motor than a lot of folks might choose. The other thing is that the four strokes make power at a lower RPM so may be best on fuel economy over the long run. The gear ratio is perhaps not as large an issue as it was when almost all of the motors were two strokes that needed the higher RPM's to get you going. The propeller's pitch can give you some of the pushing power that the old gear ratio change would give. If you don't have enough umph move down a couple of inches in pitch and gain power earlier in the curve. The four strokes definitely handle this change very well. Best; Chris "Bruce" wrote in message ... I need to buy an outboard for my San Juan 21 and not quite sure about how big to go. I would like a 4 stroke and I am thinking that about 5 HP would be a good size. Any comments about the different brands would be appreciated. Also, do I really need a "long shaft" motor. With the motor mount currently on the boat, it seems to me that any motor would easily bury the prop. Regards, Bruce |
Outboard recommendations for a San Juan 21
Chris Edmonson wrote:
... four strokes make power at a lower RPM .... That's not true for motorcycle engines so I suspect it's untrue for outboards. Four strokes *sound* like they're at lower RPM because they only fire half as often at the same RPM. Another concern might be pollution. Two strokes have more oil in their exhaust. |
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