Buying a secondhand outboard .. what to look out for

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Jemima Puddleduck

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Need to buy an outboard (long shaft) for my cruising dinghy (16 foot, 250kg Laser16). A part from all the weight, noise, smell, consumption issues between 2 stroke vs 4 stroke, consideration, what else should I be looking for? Service history? Documentation?

I’m not a mechanical petrolhead so can do very little maintenance myself.. , perhaps the impellor, spark plug, and a cleaning of a carburettor jets (from my old days as a teenager mucking around with a 2xstroke moped).. but that’s it..,!

I intend to do coastal cruising, so will have to deal with swells and tides and getting in and out of harbours, or back to the beach in a doldrum. Was thinking of a 3-5hp.
Any advise?
thanks
Manuel
 
In my experience it is all about corrosion and misuse rather than wear so really all common sense. I'd suggest that documentation is rare...

Does it start and squirt out water nicely? Will it idle?Does it look like any of the plugs, nuts and bolts might actually come undone if you tried? Things always look better inside the housing than outside so have a good look at the leg.

Also many now have a date on the label that carries the barcode, this may appear relevant but the above is what matters.
 
If you can find a 2 stoke in good condition, go for it, as it'll be a fair bit lighter than a 4. The 2T I had for 15+ years until it was stolen weighed 13kg, the 4T that replaced it weighs 18. They're also a lot less fussy about how you carry them and lay them down.

Basically, if it starts well and idles once warm, it's probably fine. A lack of water from the telltale isn't critical of itself, but may be an indication of a lack of love. Most places that service OBs will tell you that a decent but tired 2T is worth spending money on to keep it running rather than replacing with a 4T. Greta may disagree, but I was on my 3rd litre of 2T oil in 15 years of use, so I don't feel too guilty about my pollution.
 
The main thing to look for is writing "Made in China". If you see one, RUN!
BTW: I am not against Chink products in general and have some good experience with some - but outboards are definitely not among these ;-).
 
could lack of documentation indicate it could be stolen? 2T are also cheaper to buy on the whole... mmm dilemma
found a 2014 Mercury 3.5 hp 4T for £450... an older equivalent 2T would provide be £200-250..
 
Having had both, I much prefer 2 strokes and there are plenty of good ones around but, if you're worried, buy from a dealer so you have some sort of warranty. I would guess that most owners of older outboards have long since filed documentation in the waste bin so wouldn't worry about that. You say coastal cruising in 16ft boat so I would be considering 5HP or maybe even larger, doubt that a 3 will make much progress against wind, tide and chop.
 
Never seen Docs for an outboard until I bought one in Latvia ... owner had registered it with Govt CSDD.... except of course sales receipt.

Having had outboards for many years from simple Seagulls to 40HP jobs ... there are a few things I look for when thinking to buy :

1. I MUST see it run - made mistake one time - Johnson that looked nice... but when I ran it - water conduit in the leg was rotted and nothing got to the head. Power head was very good though - so I managed to sell on as spares.
2. I always tap the leg all over with a small steel ball ... not unusual to have a split leg repaired with filler .... steel ball gives distinctive sound when it hits filler.
3. I don't buy 4strokers - every KG is a pain for me at my age !!

I know its a Buying advice thread but I would like to add my Outboard use thoughts :

1. Use the proper 2T oil if water cooled, otherwise standard 2T oil in air cooled.
2. Even in 100:1 2strokers - I prefer 50:1 unless manual specifically warns about it. Reason is because many manufacturers when Environmental groups started complaining - they swapped to 100:1 ... but many found better to go back to 50:1.
3. I always run carb dry at end of day by closing off fuel and let engine run on. That way I can easily start her next session. If I stop by button and leave any of my engines (I have 2hp, 3hp, 4,5hp, 18hp, 20hp, 30hp engines of Mariner, Johnson, Evinrude, Veta, Neptune, as examples) with fuel in the carb - I have terrible trouble to start next session. But if I'm only stopping for a few hours fishing etc. - then button stop is fine.
4. I never spray with WD40 !
5. I never have trouble with 'old' gasoline. I just throw in 'fresh' to mix with it. Plus I make sure I shake the tank before opening the fuel valve / pumping fuel to carb. I have gasoline years old stored and its fine.
 
Jemima Puddleduck said:
Need to buy an outboard (long shaft) for my cruising dinghy (16 foot, 250kg Laser16). A part from all the weight, noise, smell, consumption issues between 2 stroke vs 4 stroke, consideration, what else should I be looking for? Service history? Documentation?

I’m not a mechanical petrolhead so can do very little maintenance myself.. , perhaps the impellor, spark plug, and a cleaning of a carburettor jets (from my old days as a teenager mucking around with a 2xstroke moped).. but that’s it..,!

I intend to do coastal cruising, so will have to deal with swells and tides and getting in and out of harbours, or back to the beach in a doldrum. Was thinking of a 3-5hp.
Any advise?
thanks
Manuel
Click to expand...

Wouldn't think you would need much more than a 3.5hp on a 16footer, I had a 2.5hp on a Wanderer and it went like the clappers! Not sure you need a long shaft either as the transom is quite low on a Laser 16. One thing to consider of the difference between a 4stroke and 2 stroke is the fuel consumption is much less on the 4stroke.
 
One of the difficulties I notice since new 2str Outboard motors were banned in EU - the 2nd hand price of 2str's went up and availability went down ! I know there's still healthy demand for 2str's ...
 
Jemima Puddleduck said:
Need to buy an outboard (long shaft) for my cruising dinghy (16 foot, 250kg Laser16). A part from all the weight, noise, smell, consumption issues between 2 stroke vs 4 stroke, consideration, what else should I be looking for? Service history? Documentation?

I’m not a mechanical petrolhead so can do very little maintenance myself.. , perhaps the impellor, spark plug, and a cleaning of a carburettor jets (from my old days as a teenager mucking around with a 2xstroke moped).. but that’s it..,!

I intend to do coastal cruising, so will have to deal with swells and tides and getting in and out of harbours, or back to the beach in a doldrum. Was thinking of a 3-5hp.
Any advise?
thanks
Manuel
Click to expand...
Their might be a sales receipt but a lot are owner serviced so don't expect service history. You need to try and decide (if possible) how much motoring you are likely to do as that would be the main consideration between 2 and 4 stroke for me.
 
Jemima Puddleduck said:
Need to buy an outboard (long shaft) for my cruising dinghy (16 foot, 250kg Laser16). A part from all the weight, noise, smell, consumption issues between 2 stroke vs 4 stroke, consideration, what else should I be looking for? Service history? Documentation?

I’m not a mechanical petrolhead so can do very little maintenance myself.. , perhaps the impellor, spark plug, and a cleaning of a carburettor jets (from my old days as a teenager mucking around with a 2xstroke moped).. but that’s it..,!

I intend to do coastal cruising, so will have to deal with swells and tides and getting in and out of harbours, or back to the beach in a doldrum. Was thinking of a 3-5hp.
Any advise?
thanks
Manuel
Click to expand...
A decent two-stroke every time. Unless you want to leave it permanently on a transom bracket check you can actually stow a 2.5 or 3.5 four-stroke the right way up in the storage locker on a Laser 16. At least a two-stroke doesnt care which way up it is.

2.5 hp or 3.5hp should be plenty: you're unlikely o be battling a gale and seas in a dinghy. If you can feel compression when you pull it, it starts easily and runs for 5 mins with water coming out the tell-tale it's probably fine. The 3.5s are usually the same weight/size as the 2.5s, and have a neutral so can start without drive. Stop it by turning off fuel, clean carb maybe twice a year, give it a new plug every other year (but carry one spare in case).

5 hp ought to plane a Laser 15: not sure I'd want to though. Certainly wouldn't want it's weight either stuck on the transom or having to fit it afloat. A 3.5 two-stroke used to be common power on Ruffians 23s, small cruiser-racers that weigh just short of 2 tons.
 
2.5 and 3.5 engines are frequently (always?) the same engine with different jets in the carb. 4HPs are the next size up and the next weight up - you'll notice the difference when you have to carry it any distance. 3.5 pushes my 3 tons of Snapdragon along quite happily, so I can't imagine you needing anything bigger.
 
Hi, if you can get hold of a half-decent one, one of the best is a Yamaha Malta 3.5 hp. They do appear occasionally on ebay. I've had one for years as a spare and it's always started and run. Lovely little engine. Agree with all previous about 4st. Use 50:1 fuel mix
 
northwind said:
Not sure you need a long shaft either as the transom is quite low on a Laser 16.
Click to expand...
Thanks. What is the correct way to measure? Where should the waterline be on the shaft when stationary?
Also if I can use short shaft, what would you recommend between a Mariner 3.3hp or a Tohatsu 3.5 (both 2 stroke). The Mariner looks much more recent.
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Measure from the top of the mounting pad to the waterline

If that is 15" or less a standard (aka short shaft) outboard should be correct
If more , up to 20" a long shaft is needed
20 to 25 a extra long shaft
The AV plate above the prop should be level with or a little below the bottom of the transom

BUT
for a sailing boat one size longer than indicated by measuring will put the prop a bit deeper and prevent it lifting out of the water in a bit of a chop.
This is probably not relevant to your Laser and the outboard sticking down too far will be a nuisance in a dinghy

Measure your outboard from the inside of the clamp bracket, where the top of the mounting board will be, to a point an inch or so above the AV plate ( ie a bit further down than in your 3rd photo )
About 15" - standard/short shaft, ca 20" = long shaft. 25" extra long.

As for the choice between the Mariner and the Tohatsu ... whichever is in the best condition
 
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If it’s any help Mirror dinghies used to motor with short shaft seagull outboards and being an owner of a 3.3 mercury dating from circa 2001 I would have thought it would fit a transom of like length . If you say how long a transom is on a laser 16 I’m sure other dinghy owners will tell you how it compares but merc also used to run fine on our hard dinghy as well. The only issue with them once start is that to protect the engine the pins in prop break easily so always carry spare pins on the merc and like makes eg mariner etc.
 
VicS said:
Measure your outboard from the inside of the clamp bracket, where the top of the mounting board will be, to a point an inch or so above the AV plate ( ie a bit further down than in your 3rd photo )
About 15" - standard/short shaft, ca 20" = long shaft. 25" extra long.
Click to expand...
thanks VicS, most helpful. I reckon the measurement you identified is 17” and therefore, as you recommend on a sailboat going one size bigger, that I should go for a long shaft outboard, which is what I suspected all along. Again thanks for your help.
 
ashtead said:
f you say how long a transom is on a laser 16 I’m sure other dinghy owners will tell you how it compares
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Hi Ash,
at the centreline it’s about 18.5”, however the top of mounting board is lower than the top of the transom and to the right of the centreline where the shape of the hull curves up, so it would be slightly shorter distance where the outboard is mounted. I had attacche some photos showing the transom and mounting board position with a tape measure showing the measurements (not sure if it visible)...?
 
I noticed there seemed to be some form of outboard bracket on transom so I thought perhaps it was lower than centreline measurement. I guess the simplest test is to see if you buy a secondhand merc 3.3 2 stroke on a return basis for a credit and test it or trail vessel to the outboard dealer? Don’t know if found in Seaford but for example there is a service guy at Emsworth marina whose very helpful and will sell you secondhand ones.
 
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