2.5 or 3.5 hp tender outboard

[CAPTAIN FANTASTIC]

I have both the Suzuki 2.5 hp four stroke and the Tohatsu 3.5 hp four stroke (Mariner and Mercuri 3.5 is a Tohatsu engine). I bouth the Suzuki 2.5 because I wanted a light engine; its 13kg and brilliant, will go on the plane with an inflatable 2.9 and me (15 st). The Tohatsu/Mariner 3.5 is much heavier and although more powerfull, the extra weight makes it difficult to move up and down the boat.

 

[BelleSerene]

I have both the Suzuki 2.5 hp four stroke and the Tohatsu 3.5 hp four stroke (Mariner and Mercuri 3.5 is a Tohatsu engine). I bouth the Suzuki 2.5 because I wanted a light engine; its 13kg and brilliant, will go on the plane with an inflatable 2.9 and me (15 st).

That's amazing! I weigh less than that but my Suzuki DF2.5 can never get my inflatable Zodiac 2.85 inflatable floor tender on the plane. What am I doing? Could it be because of the inflatable sausage in the sole which makes a V shape in my hull, or does yours have that too?

 

[TSB240]

Nobody has recommend the lightest and most powerful engine that would suit your needs. We have been using a twin cylinder 2T johnson/evinrude 4hp for years. They still often come up for sale with very low hours. I don't think even the horrible noisy air cooled converted Honda lawn mower is lighter. Nearly twice the power for the same weight. Easily gets our large flubber on the plane. Never fails to start easily and can be thrown any way you like in a locker. Best 2t little motor ever made. I still have an ancient yachtwin of the same design 45 years old and still working.

 

[CAPTAIN FANTASTIC]

That's amazing! I weigh less than that but my Suzuki DF2.5 can never get my inflatable Zodiac 2.85 inflatable floor tender on the plane. What am I doing? Could it be because of the inflatable sausage in the sole which makes a V shape in my hull, or does yours have that too?

Mine is an old Wetline 2.9 with an inflatable V hull and with solid plywood floor panels (no slatted floor). It has been a good dinghy and after 11 years of abuse, it will be replaced next season with the same or similar. The Suzuki 2.5 will go on the plane when I sit in the middle front of the dinghy. The Suzuki is a brilliant engine; same weight as two stroke. I understand from some foroumites on here had problems with the carburetor jets getting blocked; so far, I have not had any issues.

 

[[3889]]

I The Tohatsu/Mariner 3.5 is much heavier and although more powerfull, the extra weight makes it difficult to move up and down the boat.

Yep, got the Tohatsu and it's weight often disuades me from bothering with it, especially in any sort of lumpiness. It will get my 2.6m 3d tender on the plane two up, just.
I was thinking of the Honda 2.3 as a replacement but not so sure after this thread. I had bad experiences with 2 Suzuki bikes so not keen on the brand.

 

[BelleSerene]

I was thinking of the Honda 2.3 as a replacement but not so sure after this thread.

It's light, and the centrifugal clutch is great: at idle it just takes itself out of gear which makes coming alongside really easy. Its plastic prop gets chewed up by gravel. It’s air cooled which could be helpful if you’re driving it through a lot of seaweed which could otherwise block the water inlet - but by God, chucking all its vibrations into the air makes it noisy. I was happy to change brand when mine was lost overboard - but the Suzuki is troublesome in its own way.

 

[dancrane]

Coincidentally, I've been looking at a sub-1,000kg lift-keeler with a long shaft Suzuki 2.5hp as its auxiliary.

It's had less than ten hours' use, so I'm hopeful that (if I were to buy the boat) it's probably new enough not to have suffered from neglect - or from maintenance that might have been appropriate for other engines, but wasn't prescribed for this one.

So...separately from the OP's question regarding use with an inflatable, is the disputed Suzuki 2.5 likely to be powerful enough as auxiliary for for an 'eighties trailer-sailer? I imagined a high-freeboard design needs a bit more grunt to be responsive under power.

 

[prv]

We have been using a twin cylinder 2T johnson/evinrude 4hp for years. [...] Best 2t little motor ever made.

I have one in the shed. It’s certainly neat, very light for the power, and fairly quiet by 2-stroke standards - but mine has never been reliable. Test running it in a bin it would always end up stopping and refusing to restart; eventually after much fiddling with the carb it seemed to keep going, so I took it out on the river whereupon it died after about fifteen minutes. Fortunately I had also brought as backup my 2.5hp Suzuki because I didn’t trust the Johnson. I’ve basically given up on it at this point.

Pete

 

[Fossil]

Just a thought, but if anyone is looking for a source of 100ml screw-top brown plastic bottles, but doesn't want to buy in bulk, all pharmacies have them for dispensing purposes and would I am sure be happy to let you have one or two for a fairly minimal outlay.

 

[oldmanofthehills]

Coincidentally, I've been looking at a sub-1,000kg lift-keeler with a long shaft Suzuki 2.5hp as its auxiliary.

It's had less than ten hours' use, so I'm hopeful that (if I were to buy the boat) it's probably new enough not to have suffered from neglect - or from maintenance that might have been appropriate for other engines, but wasn't prescribed for this one.

So...separately from the OP's question regarding use with an inflatable, is the disputed Suzuki 2.5 likely to be powerful enough as auxiliary for for an 'eighties trailer-sailer? I imagined a high-freeboard design needs a bit more grunt to be responsive under power.

My old snapdragon which had similar weight had a 5 hp Mariner and that was OK but kept me to less than 4kts under power - which unfortunate when I hit 4kt tide outside Portishead harbour and couldnt get in. So my reaction is that 2.5hp is fine if you sail in still waters and just use it to go down marina but rather meagre otherwise

 

[RichardS]

I have one in the shed. It’s certainly neat, very light for the power, and fairly quiet by 2-stroke standards - but mine has never been reliable. Test running it in a bin it would always end up stopping and refusing to restart; eventually after much fiddling with the carb it seemed to keep going, so I took it out on the river whereupon it died after about fifteen minutes. Fortunately I had also brought as backup my 2.5hp Suzuki because I didn’t trust the Johnson. I’ve basically given up on it at this point.

Pete

Before we had our own boat we used to charter frequently with the same company and after a few years we realised that when we arrived at the boat it would either have a 5HP Johnson or a 5HP Mercury on the tender. If it had a Johnson, the first thing I would do is get the company to swap it for a Mercury as it was the only way to guarantee a trouble-free holiday. :ambivalence:

Richard

 

[stevd]

Thought I would give an update to the thread.....

Decided to go with the Suzuki due to the weight element. I am hoping it will encourage me more to use it. I did go to the boat show and lifted both....whilst the Mariner 3.5 at 17kg is definitely manageable, it is still going to be easier with the 13kg one. I just hope I wont miss the power too much.

Next decision....... do I keep the yammy 4hp 2 stroke in case I do decide to buy a dedicated shore to mooring tender or just get it sold on........ any ideas what they are worth....its scruffy but working.

 

[Heckler]

There seem to be so many threads about the shortcomings of small four-stroke outboards, I hardly know where to look first...

...can anybody explain simply, if the four-stroke process is intrinsically temperamental or vulnerable on outboards, or whether the manufacturing is at fault, or if lots of users are insufficiently careful about observing the recommendations for storage and cleaning?

I'll be buying an outboard at some point, and while I'd prefer a well-preserved two-stroke, I'd like to believe there are dependable NEW engines available...God knows, they're not cheap. Considering how clever and reliable, most Japanese petrol engines are reputed to be, it seems odd that small four-strokes have found so many unhappy customers.

California and tree hugging bunny lovers insisted on 4 stroke to save the planet! Then the lean mixture required to meet the emission specs at tickover led to tiny and fixed pilot jets in the carbs. Then E petrol came along with 5% bio in it, ie alcohol, which is hygroscopic, it absorbs water from the atmosphere this reacts with the metals in the float bowl to help block the jets. Again the save the planet tree huggers although the fact that it uses corn as feed to produce the alcohol? Oh never mind the poor third world countries who are going hungry because we now use food to produce alcohol to produce alledged emission free fuel! Also a thought, at one point, cooking oil in the EU was cheap, not any more, about a quid a liter, ponder a thought, people a few years ago found out that their diesel cars would run on cooking oil, hey ho the price of it has gone up so now its hardly worth doing! Conspiracy theory? Moi, nah! Im just a cynical old barsteward!
Anyway to the originsl subject, someone on here experimented with their Suzy, bought a small drill bit and drilled the pilot jet out, heyho, decent rich tickover mixture and probs go away! The op can do a search and find the thread fir the size.

 

[TQA]

If you want to plane reliably two up 8 hp is the minimum, 10 hp is better and most cruisers have a 15 hp or more on their RIBSs.

While I have seen a Tohatsu 3.3 on the plane it was a small person in a baby AX 1 or 2 and they were hanging over the bow. Just don't expect anything less than 8 hp to get up on the plane 2 up reliably. It ain't gonna happen.

 

[dancrane]

My old snapdragon had a 5 hp Mariner and that was OK but kept me to less than 4kts. So my reaction is that 2.5hp is fine if you sail in still waters and just use it to go down marina but rather meagre otherwise.

Agreed. Makes me wonder why the previous owner of the Hunter I looked at, went for a Suzuki 2.5 as auxiliary.

...the lean mixture required to meet the emission specs at tickover led to tiny and fixed pilot jets in the carbs...someone on here experimented with their Suzy, drilled the pilot jet out, heyho, decent rich tickover mixture and probs go away!

That's very encouraging. :encouragement:

 

[Tam Lin]

California and tree hugging bunny lovers insisted on 4 stroke to save the planet! Then the lean mixture required to meet the emission specs at tickover led to tiny and fixed pilot jets in the carbs. Then E petrol came along with 5% bio in it, ie alcohol, which is hygroscopic, it absorbs water from the atmosphere this reacts with the metals in the float bowl to help block the jets. Again the save the planet tree huggers although the fact that it uses corn as feed to produce the alcohol? Oh never mind the poor third world countries who are going hungry because we now use food to produce alcohol to produce alledged emission free fuel! Also a thought, at one point, cooking oil in the EU was cheap, not any more, about a quid a liter, ponder a thought, people a few years ago found out that their diesel cars would run on cooking oil, hey ho the price of it has gone up so now its hardly worth doing! Conspiracy theory? Moi, nah! Im just a cynical old barsteward!
Anyway to the originsl subject, someone on here experimented with their Suzy, bought a small drill bit and drilled the pilot jet out, heyho, decent rich tickover mixture and probs go away! The op can do a search and find the thread fir the size.

Yes, I did that after reading it on here. It did make a difference but the engine is still crap. Anyone want to buy one?
Keep the Yamaha, you’ll need it.

 

[RichardS]

Yes, I did that after reading it on here. It did make a difference but the engine is still crap. Anyone want to buy one?
Keep the Yamaha, you’ll need it.

The OP has plumped for the brilliant little Suzuki 2.5. Perhaps he's intending to follow the advice in post #18.

Richard

 

[stevd]

I have to say it looks very straight forwards to drain the carb with a convenient drain cut out in the casing at the bottom so shouldn't cause too much hardship to drain each time. Is this the case with most engines?

 

[RichardS]

I have to say it looks very straight forwards to drain the carb with a convenient drain cut out in the casing at the bottom so shouldn't cause too much hardship to drain each time. Is this the case with most engines?

It is easy to drain. I bought a short length of fuel hose so I could easily incorporate a tiny in-line fuel filter (this type of thing https://www.ebay.co.uk/itm/10Pcs-Qu...rt-Pit-Bike-Minimoto-Motorcycle-/123282429753 ) and I then pushed a couple of inches of the tube onto the drain spigot so it protrudes just below the bottom of the casing to make draining into a can even easier.

One more tip: when you first get the engine, completely unscrew the drain screw (it has a spring on it) and grease the thread and then re-insert it. This will stop it stiffening up in a couple of years time.

Richard

 

[CAPTAIN FANTASTIC]

A year ago, I left my Suzuki 2.5 lie-down, accidentally, the wrong way for at least 5 hours. I picked it up thinking that there would be oil everywhere, in the carb, in the cylinder etc., I decided to pull the cord; the engine started; no smoke, no issues.