I have always assumed that an inboard would be the engine of choice on a 27, but does anyone know if there are advantages of an outboard in a well. More interior space perhaps?

Also whats the view on Yanmar vs Buhk?

I am about to buy so would welcome some help advice

After having spent 12 hours slamming my way back yesterday coming from the isle of man into a force 5 on the nose i can happily recommend the inboard rather than outboard, if the outboard option was taken it would have spent more time in the air than the water, even if it was in a well it would only work for motorsailing on one tack only.
Good boats though the 27 and sadly i am selling mine to buy larger as the family are all growing.

Hi Steve. I used to have an outboard on a P21 then changed to inboard on the P275. I much prefer the inboard approach. The main difference is fuel. With an outboard, fuel consumption and range was always on my mind. With an inboard, I think about fuel every few months. I can't comment much on Bukh vs. Yanmar. We have a few members with a Bukh, and they are pleased. But then so are Yanmar owners (me!). My 1GM10 starts without fuss and just keeps on going.
Happy buying!

Ken Surplice
Commodore

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I've got a twin cylinder fresh water cooled Yanmar inboard diesel on my P27, but that's largely because that's what the boat that I most liked in all other respects happened to be fitted with!

Would I have bought the self-same boat if it had been outboard engined? If it was transom hung - no way! If it was in a well, then absolutely Yes, with the following caveats: I would expect to have to supplement engine charging with wind or solar charging, and, if the outboard was not one of the models marketed as a sailing boat auxiliary, I would have immediately changed it.

This is because such models have a longer shaft than the standard Longshaft length of 22"/56cm so as to place the prop even deeper in the water for better grip and to ensure that it does not come out of the water when the boat is pitching heavily; and they have a much finer pitched, larger diameter, larger blade area prop to focus the power on thrust rather than speed: and they have a modified exhaust system to relieve the back pressure that comes from immersing the exhaust deeper in the water; and most will also feature a propellor that deflects the modern through hub exhaust when in reverse, so that full reverse thrust is maintained.

Just don't expect an ordinary Longshaft non-sail boat outboard to be effective for the converse of all the points above.

I love outboards, especially 2-strokes for their inherent simplicity and reliability, and for the fact that they are far cheaper to buy, & replace than an inboard, far simpler in their installation, far simpler to service [whip them off & take ashore!] and are totally self contained - no mountings to fail, no couplings to vibrate, no shaft to wear, no shaft seal to leak, fouled props easily cleared, damaged props cheap to replace, etc, etc.

But Ken is right - range is an issue - a standard 23 litre outboard tank will be totally inadequate & you don't want to be fiddling with multiple portable tanks, let alone plastic fuel cans, so you should have one large [or two interconnected] fixed tank(s). 4-strokes will use 40% less fuel than 2-strokes, but need more professional care and maintenance than 2-stroked.

If you do go Inboard diesel [and almost all 27's are inboard], and if you have a choice, go for Bukh because they are purpose designed marine engines whereas Yanmar, good as they are for their type, are just another marinised high speed commercial diesel. In an ideal world, get an Indirectly Cooled [fresh water] model - it will have much longer life than an engine that is Directly Cooled [raw water].

Good hunting!






Geoff Sheddick
Parker 27/146 "Stroller'

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Thanks Geoff, I very comprehensive reply!
Just need to find a boat now...
Cheers
Steve

Miss Fidget has an outboard in a well, and the attached photos show its position. The propeller is at a very similar depth in the water to that of an inboard propeller. As the boat pitches, the propeller will rise higher than an inboard propeller because it's a little further aft, but we've never had any concern that the prop might come out of the water, even heading out of Chichester Harbour in strong wind against tide conditions. And I can't think of any reason why motorsailing would work on one tack only - am I missing something, Sean?

The outboard is a Tohatsu 9.8HP two-stroke standard shaft with the saildrive propeller. From our experience, the standard shaft is fine. The prop is deep enough - and could be placed still deeper by an adjustment of the sliding bracket the outboard sits on - and the engine can be lifted high enough to get the prop almost out of the water when we're away from the boat, thereby reducing the fouling problems (though the skeg is still in the water, and that does grow barnacles!). The saildrive propeller is crucial, giving us reasonable control astern as well as forward. The exhaust gases are automatically directed out of the propeller in forward gear and much higher up in reverse.

An outboard has the advantages others have mentioned and I would add ease of freeing of fouled propeller and improved sailing performace when the plug is inserted into the well beneath the raised outboard. Disadvantages also are as already mentioned, and in addition the noise. I guess a four-stroke outboard would be quieter, but also heavier and larger.

When we bought Miss Fidget, we investigated changing from the outboard to an inboard option, but decided against on the grounds of cost. After five years with the outboard - and particularly since changing the propeller to the saildrive version - we're very happy with it.

Gilliane

Miss Fidget, Super Seal 26, no. 69

PS I should have said that the photos show the original propeller, not the saildrive version we currently use.

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Hi, I have been directed to this topic due to raising a simlar question on the seal 22 Forum.

I am wondering if Gilliane wold be able to post a picture of the sail drive propeller she has on her Tohatsu 9.8 Hp.

I beleive yours may be slightly older than mine as I purchased mine approxamatly 4 yrs ago (New) I was told I have the sail drive propeller but having looked at your picture I beleive its the same propeller.

Thanks Ray

Dear Ray

I took some photos this afternoon of our saildrive outboard propeller, and attach a couple. The front aspect shows that the edges of the propeller have lost quite a bit of paint, but the most obvious difference from the earlier photo is in the side view, where the angle of the blades on the two props is quite different. (You can also see the effects of the barnacles on the skeg - scraping them off doesn't leave an entirely smooth, clean surface!) I contacted Tohatsu by e-mail (engineer@tohatsu-uk.net) and got a very specific recommendation for our outboard, including the order code.

Hope this helps

Gilliane




Miss Fidget, Super Seal 26, no. 69

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Hi Gilliane

I inherited an 8hp Mariner Saildrive with my Super Seal, but I have been frustrated by the performance, only managing 3.5knots flat out.

I'd be interested in what sort of crusing speed you can manage with the 9.8, as I'm thinking of upgrading.

(For any that is interested, you can still buy 2 stroke engines new in the Channel Islands as they are outside the EU).

Dear Stargazy

We've never run our outboard flat out, but we measured our speed in Cowes last week, and got over 5 knots in calm water, against practically no tide. I'm afraid I don't know how far away we were from maximum revs.

Incidentally, since listing the advantages and disadvantages of an outboard in an earlier post, we've experienced another advantage: if we're trying to conserve the battery for any reason, it's easy to start on the pull cord!


Gilliane

Miss Fidget, Super Seal 26, no. 69

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quote:

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Originally posted by Gilliane Sills

Dear Stargazy

We've never run our outboard flat out, but we measured our speed in Cowes last week, and got over 5 knots in calm water, against practically no tide. I'm afraid I don't know how far away we were from maximum revs.

Incidentally, since listing the advantages and disadvantages of an outboard in an earlier post, we've experienced another advantage: if we're trying to conserve the battery for any reason, it's easy to start on the pull cord!


Gilliane

Miss Fidget, Super Seal 26, no. 69

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Hi Gilliane

Many thanks for the reply, thats good to hear, I have been so frustrated this year, our engine seems to produce a lot of frothy water, and not much forward motion. I have looked at changing the propeller, but there are no others available for our engine model, so I think I shall save up and replace it with a new Tohatsu.

Thanks again

Daniel

Hello Daniel,

I am quite surprised by your statement that there are no other propellors available for your Mariner 8hp Saildrive, and I encourage you to persevere with your research before going to all the expense of changing your engine.

Of course I don't know the age or the type [2T or 4T] of your engine, nor the extent of your enquiries, but I wonder if you know that all smaller Mariner & Mercury 2T outboards of whatever vintage are identical under their cowlings, so all parts for a given year/model are interchangeable?

http://tinyurl.com/3zzwh8n  - you'll see that the prop is potentially available in several different pitches - you need a small pitch [=lower gearing], high thrust prop which will better match the high shaft rpm to the slow speeds that a sailing cruiser can achieve - the blades will be visibly much larger in area than the larger pitch props.

Its also worth bearing in mind that if your Mariner is older than 1983, then its power will have been rated at the crankshaft, not at the prop, so in today's terms, it would only be rated at about 6hp.

Good hunting!

Geoff Sheddick
Parker 27/146 "Stroller'

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quote:

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Originally posted by geoff.sheddick

Hello Daniel,

I am quite surprised by your statement that there are no other propellors available for your Mariner 8hp Saildrive, and I encourage you to persevere with your research before going to all the expense of changing your engine.

Of course I don't know the age or the type [2T or 4T] of your engine, nor the extent of your enquiries, but I wonder if you know that all smaller Mariner & Mercury 2T outboards of whatever vintage are identical under their cowlings, so all parts for a given year/model are interchangeable?

http://tinyurl.com/3zzwh8n  - you'll see that the prop is potentially available in several different pitches - you need a small pitch [=lower gearing], high thrust prop which will better match the high shaft rpm to the slow speeds that a sailing cruiser can achieve - the blades will be visibly much larger in area than the larger pitch props.

Its also worth bearing in mind that if your Mariner is older than 1983, then its power will have been rated at the crankshaft, not at the prop, so in today's terms, it would only be rated at about 6hp.

Good hunting!

Geoff Sheddick
Parker 27/146 "Stroller'

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Hi Geofff

Thanks for the link, I took the prop into Ron Hale to enquire about different one, and they said only one was available!

I'll try another dealer.. There is nothing wrong with the engine, it starts first time, and never misses a beat, so I am loathed to change it, however the lack of forward movement is very frustrating, and massively increases journey times.

Its a 1998 8Hp. I emailed Tohatsu and they recommended: "The dimensions for the propeller are 4 blade x 8.7 diametre x 5 pitch."

There is a guy at Emsworth who has a good reputation, so I shall enquire with him.

Thanks for the ideas, much appreciated.

Regards

Daniel

Daniel,
If Tohatsu can offer their own brand 4 blade, 5" pitch prop that will fit your Mariner, I'd go for it! Just check that it is a genuine Tohatsu prop and not some funny shaped aftermarket special [such as I have seen on the web] that Tohatsu UK happen to be marketing...
4 blade will give much better 'bite' than 3 blade thanks to its much larger surface area, and 5" pitch sounds good to me [the reason why your outboard prop pitch needs to be about half that of an equivalent inboard engine prop is that the shaft rpm of the outboard is about twice that of the inboard].
But it'll do no harm to check with Bill Mitchell, of Home Marine at `Emsworth [01243-374125] - he's been in the business at least 20 years, and in his location, is well used to dealing with sailing boat auxiliaries.
I'd be interested to know how you get on, if you have a moment.
Geoff

Geoff Sheddick
Parker 27/146 "Stroller'

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Daniel,

I am probebly braking some rule But.

I'm in the process of changing boat and may decide to sell my 9.8 Tohatsu 9.8 Four stroke about 4-5 Years old, serviced every year

Although I may sell it with Sealia 22'Seal.

If your still thinking about it contact me hrh15jATntlworld.com

I may keep it as a spare for new boat

Regards

Ray

quote:

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Originally posted by Ray

Daniel,

I am probebly braking some rule But.

I'm in the process of changing boat and may decide to sell my 9.8 Tohatsu 9.8 Four stroke about 4-5 Years old, serviced every year

Although I may sell it with Sealia 22'Seal.

If your still thinking about it contact me hrh15jATntlworld.com

I may keep it as a spare for new boat

Regards

Ray

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Hi Ray

Thanks for the offer, unfortunately a 4 stroke of that size will not fit in my seal's outboard well.

How did you find the weight of a 4 stroke on the back of a 22? It seems a huge lump to put on the back of a small boat!?

Sorry, It is a TWO stroke (I must have dosed off while writing). Still not sure if I will sell it as new boat has a problem with inboard engine and had to use it on Sunday from fishbourne to portchester will make decision at start of next year.

Dear Daniel

I'm intrigued to hear that Tohatsu have suggested a four bladed prop. When I contacted them last summer (2010), I described the problem we had going astern (ok to manoeuvre at slow speeds but not able to use reverse gear to slow down forward motion) and the reply was "We have had a standard 3 blade Tohatsu propeller specially modified for the problems you are experiencing". We had previously been using a Solas four-bladed prop which had been described as 'Hi-thrust' for the Tohatsuu 9.8, but we felt it wasn't very effective, so we were happy to try the new recommendation. We've been pleased with it - it certainly is better than before - but this experience suggests that a four-bladed prop isn't necessarily better, though I understand Geoff's argument about a bigger area giving better 'bite'. Perhaps this four-bladed prop is a new design and is even better than the one Tohatsu recommended last year!

I think it's possible that some of our satisfaction with our present propeller is due to becoming more familiar with the limitations and learning to live with them - for example, if we think we'll want to slow down when entering a marina berth with the tide taking us in, we now go in astern so that we can use a burst in forward gear to slow down.

Best wishes

Gilliane



Miss Fidget, Super Seal 26, no. 69

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