Worth upgrading to a 4 stroke o/b?

[QBhoy]

I would f bother changing over at that size and the engine you have now. More trouble than it’s worth. Loads of issues with cheap carbs and oil running back from sump into the carb too. Even when stored the right way. If you’re used to pulling an old 2 stroke out the garage after sitting for years…then just starting like they always do…you won’t want to change to a wee 4 stroke and expect the same. My thoughts

 

[Kelpie]

Most cruisers that spend time in the Caribbean splash the cash and opt for a 10 or 15 hp 2 stroke and a 9 or 10ft rib.

That would certainly be very practical. Our lack of deck space (babystay) and unwillingness to cross an ocean with a dinghy in davits put me down the route of building a nesting dinghy.
I absolutely love the dinghy, it rows like a dream and carries an enormous load effortlessly. And sailing it around the anchorage is fun too.
I had originally hoped that I could put a bigger outboard on it and get it planing but it's just not designed for that. The biggest motor I've heard of being used in this design is 6hp. It seems an awful lot more weight not a great deal of extra power.

If a faster fight proves essential, we will just have to either pick up a secondhand RIB which can live permanently in davits, and sell it when we leave, or get an air-floor roll up rated for 10hp or more.

 

[Neeves]

Re the comments about weight, I'm pretty much specifically comparing my current Mercury 2.5hp with a Suzuki 2.5hp 4t. Both should be about 12-13kg.
I appreciate there is a huge weight difference once you start looking at bigger outboards.

Our 2.5hp 4t Suzuki is significantly heavier than our 2 hp 2t Yamaha. The Suzuki needs to be laid down 'specifically', the Yamaha any old which way. Not a problem - except that helpful mate does not know this and when you turn your back he has laid it down incorrectly - oil on the spark plug .

Admittedly small engines. Cannot tell any difference in performance (except the Suzuki starts first time - unless a helpful mate has been around!). Ours is a genuine egg whisk - cannot comment on an industrial scale dough processor.

I'm interested to hear that you saw noticeably more power with the new engine. Of course you went from 2.2 to 2.5hp.

I'm taking a pretty elderly engine which is theoretically 3.5hp and switching to a new 2.5hp... I'd like to think I'll see a slight increase in power but it's probably wishful thinking. Does anybody know how outboards age? Do they lose a bit of power over the years?

Outboards fail for reasons other than loss of power or old age - in my experience - corrosion is the common issue.


We don't use our OB in rough waters nor strong winds - its very much for shore to yacht in flat water. If it were windy we would be moving the yacht to somewhere more sheltered and as we only draw 1m we can usually get close to shore - so we only need a small OB. I don't know but if you need the OB for significant journeys (it would be bigger) and maybe with bigger OB different factors are of importance. For 'exploring' we have kayaks. Geem's needs (and thus specification for his OB) in the Caribbean is very different to ours around Sydney and Tasmania (we don't shop and revictual - no shops, self sufficient for 3 months......)

And we also have a weight fetish

Horses for courses.

Jonathan

 

[Refueler]

I'm interested to hear that you saw noticeably more power with the new engine. Of course you went from 2.2 to 2.5hp.

I'm taking a pretty elderly engine which is theoretically 3.5hp and switching to a new 2.5hp... I'd like to think I'll see a slight increase in power but it's probably wishful thinking. Does anybody know how outboards age? Do they lose a bit of power over the years?

The 4str will have a different prop pitch / diameter to compensate for the rpm / torque curve difference.

 

[geem]

That would certainly be very practical. Our lack of deck space (babystay) and unwillingness to cross an ocean with a dinghy in davits put me down the route of building a nesting dinghy.
I absolutely love the dinghy, it rows like a dream and carries an enormous load effortlessly. And sailing it around the anchorage is fun too.
I had originally hoped that I could put a bigger outboard on it and get it planing but it's just not designed for that. The biggest motor I've heard of being used in this design is 6hp. It seems an awful lot more weight not a great deal of extra power.

If a faster fight proves essential, we will just have to either pick up a secondhand RIB which can live permanently in davits, and sell it when we leave, or get an air-floor roll up rated for 10hp or more.

Our dinghy is also nesting. It is 12'5 (3.8m) long when assembled. 7ft long when nested. We cross oceans with it on the deck. We have a baby stay. The dinghy sits on the deck just in front of the baby stay. From the front of the dinghy there is still 7ft of deck to the bow.
Our dinghy is grp with grp cored bulkheads. It's also a sailing dinghy but crucially we use a 15hp engine. We can plane with 4 adults onboard. The dinghy is 30 years old.

 

[doug748]

In many parts of the Caribbean I would be happy to have the scruffiest outboard on the beach. A new one might have the life expectancy of an NCO on the Western Front.
More than 5-6 knots on a rowing dinghy would not be for the faint of heart.

 

[geem]

Here a squall going through our anchorage a couple of days ago. 35kts on our masthead wind instruments. We have had several of these squalls over the last few days. Can you imagine being caught out in one of these in a small dinghy and engine. Not just wind but skin stinging rainfall. Fortunately they don't last long but even without the squalls it's been a solid 24kts some days.

 

[geem]

We are sat at anchor. A breezy night but pretty normal for here. Just having the morning cuppa. 4 hrs behind UK time. Wind instruments says 22/24kts. Nice sunny morning but a big cloud on the horizon, currently 24DegC but its only 0650 as I write this. Weather radar shows a squall heading our way. Bank on 5 to 10kts over gradient winds for squalls. This one looks like a biggy. So probably over 30kts. Anchored with 4:1 scope. A normal Caribbean morning
A dinghy/engine combo that can deal with this is an asset. Those that don't have the decent set up get constrained where and when they go. There is quite a chop getting on and off the boat even though our heavy boat doesnt move. No advantage of a sugar scoop. The one to two foot chop makes is far easier to get on and off the boat with a vertical transom and fixed ladder. Lots of easy handholds. Sailing here is not like UK/Med. The ideal set up on your boat is somewhat different. Cruisers only go into marinas if they need repair work or they are leaving the boat to fly home. Here life is at anchor

 

[Kelpie]

Our dinghy is also nesting. It is 12'5 (3.8m) long when assembled. 7ft long when nested. We cross oceans with it on the deck. We have a baby stay. The dinghy sits on the deck just in front of the baby stay. From the front of the dinghy there is still 7ft of deck to the bow.
Our dinghy is grp with grp cored bulkheads. It's also a sailing dinghy but crucially we use a 15hp engine. We can plane with 4 adults onboard. The dinghy is 30 years old.

It sounds absolutely perfect. I know you've talked about it on here before- from memory it's not much heavier than my own dinghy, which is somewhere in the region of 40-45kg (I forgot to weigh it when I'd finished building!)

My dinghy just isn't designed to plane. Too much rocker, which makes for good sailing and rowing. With just me onboard it sits at about 6.5kt with the bow in the air. One of these days I'll make up a tiller extension...

P.S whereabouts are you? We're currently in Deshaies, Guadeloupe.

 

[geem]

It sounds absolutely perfect. I know you've talked about it on here before- from memory it's not much heavier than my own dinghy, which is somewhere in the region of 40-45kg (I forgot to weigh it when I'd finished building!)

My dinghy just isn't designed to plane. Too much rocker, which makes for good sailing and rowing. With just me onboard it sits at about 6.5kt with the bow in the air. One of these days I'll make up a tiller extension...

P.S whereabouts are you? We're currently in Deshaies, Guadeloupe.

We are at Green island, Antigua. We were in Deshaies last week.
We will be in Falmouth on Thursday. We have friends flying out for a couple of weeks at the weekend