Buying an outboard motor for your boat

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I'll start this guide off by saying that Ebay probably ISN'T the best place to buy an outboard for your boat. There's far too much that can be wrong with one that a lot of people are completely ignorant of-and a LOT of sellers either know no better or are habitually stupid and pathological liars.The difference between buying a car and an outboard from a pathological liar is that your life can depend on the outboard. There's no hard shoulder or layby when the engine breaks down as a cross channel ferry is bearing down on you and drowning is a very bad career choice.

This guide is pretty basic but it should help you to avoid some of the more common lies/mistakes listed by sellers.

What to look for

First check the weight and horsepower rating for your boat-overpowering a boat may result in bad handling, your insurance company will have a field day if you have an accident and it may well damage your transom (eventually resulting in it falling off)-or worst case you may sink a displacement hulled open boat with too much throttle.

You will (for use at sea) probably want at least 2/3 of the max HP rating-for example a 5.4m Avon Searider (rated to 90hp) won't go very well at all with a 40hp but will be good with 60-90hp. It's pointless underpowering a planing hull-the engine will be straining to get it to plane and when planing will use more fuel for a given speed than a bigger engine with less throttle opening.



You need to see the engine running and make sure that the cooling system is working properly. The cooling system will be obvious by a 'telltale' or 'pee stream' of water coming from the engine.In most cases No telltale= no cooling=cooked/overheated worthless and damaged motor-unless the motor is air cooled.


If you or the seller runs a non aircooled engine out of water the cooling system impeller WILL BE DESTROYED IN SECONDS. This can cost anything up to £200 to fix depending on the damage done and the engine-and that's NOT including overheating damage done to the rest of the engine. If the seller is stupid enough to show an outboard running  without cooling water then stay well clear. The chances are the motor has been cared for with a lump hammer.

Ask what grade of 2-stroke oil the seller has used. If it's not TCW3 approved oil and it's been used with non TCW3 oil for  long time then avoid it. TCW3 is a low ash oil designed to stop coking up of engines that are constantly run under heavy load and is the ONLY grade approved for most outboards. Ignore the nay-sayers-everyone knows one and they'll be the ones grumbling at the prices to fix their engines when they find out they are wrong.

Ask if the seller has compression figures for the engine. If they haven't and you know how to use a compression tester then ask to test them yourself. It's only about £20 to buy a compression tester-and it could save you hundreds or even thousands depending on purchase price if you're looking at a dud engine. Compression figures vary but they should be within 10% of each other. Readings below the 10% indicate abnormal wear in that cylinder and the motor probably needs a rebore and new pistons. This will be EXPENSIVE.


Buying a Non-runner.

1)DON'T DO IT UNLESS YOU KNOW WHAT YOU'RE DOING WITH AN OUTBOARD.Knowledge of 2-stroke bikes and cars isn't enough.

2)Unless you've done it before, expect spares to be twice the price of car/bike spares. If it's for marine use it WILL be overpriced.

3)Expect EVERY bolt to be siezed. Most outboards are used in salt water. It rots things like acid does.

4)Don't pay more than it's worth for scrap. You've got a 50/50 chance that's what it will be.

What you're looking at-Types of outboard.

Shaft length.

This is measured from the antiventilation plate (the flat plate just above the propeller)to the part of the clamp that SITS on the transom-ie the underside of the clamp as in the picture. It is NOT measured from the top of the clamp to the centre of the propeller and it has nothing to do with how tall the engine is. There are generally 3 shaft lengths-Short(17-18"),long(20-21") and Extra-long(25") and these coincide with the height of your boat's transom. Unless someone has hacked your boat about, one of these will fit your boat.

Fuel Consumption

This is best calculated at WOT (Wide Open Throttle) to ensure you don't run out and should not exceed 10% of the horsepower of the motor in GALLONS PER HOUR. For example a 50hp will use around 5 gallons per hour at WOT. Modern outboards use less but still use this as a rule of thumb and you'll never run out.Always carry 1/3 extra fuel in reserve and cycle it so it doesn't go stale.If you can't afford the fuel consumption don't buy the boat/engine.

Manufacturers/brands to avoid like the plague

Crescent/Archimedes/Penta/Volvo or any combination of these names. View these as disposable. Your chances of finding new spares are slim as they've been out of business since the 1970s. Build quality not too bad but very heavy.

Chrysler and Force- Badly built down to a price using old technology so they fall apart. Any still running are a miracle-they are absolutely awful and spares availability is as bad as the engines.Force Brand ceased to exist over 15 years ago,Chrysler branded outboards have been out of production for over 20 years. Force are mostly Chrysler parts-I can't emphasise enough how bad these engines are.. Don't touch it unless you're absolutely desperate and it's as good as free. Pay no more than scrap aluminium price for them.

Anything Chinese that doesn't look refined-The current crop of Chinese outboards are atrocious.Anything that looks like a lawnmower motor bolted to a pole will rot to bits in 2 years.Don't bother unless free.

Common lies/mistakes in Listings

It's a Mercury Blueband from the 1980s-No, it's probably from the 1970s. If it has distributor ignition it's from the 70s and can be as old as 1972. Imagine working on something that old that's been in salt water. Most dealers won't touch them anymore.

It's a Mercury Red Band from the 1980's-No, it's probably older than your parents. Redbands were superceded by bluebands in 1972. Most are from the 1960s. Expect it to be scrap in disguise.

It's an Electric Shift Johnson-I'm keeping the controls-It's from the late 60s/early 70's and unless it comes with the original control box it's useless as it'll be stuck in forward gear. No other controls will fit this engine.The seller probably realised this too late after buying it and is trying to pass it on to you.

I think it's aircooled-Make sure it IS or you're in for a big repair bill as they've probably been running it without cooling water.

I ran it for a minute out of water to test it(or variations)-Run away. This guy hasn't got a clue and you're probably buying a heap of trouble. The water pump impeller will be fried, the housing has probably melted and even in that short space of time there can be major engine damage. Pay no more than scrap aluminium price unless you want non-mechanical parts from it.

Age of the Engine

Always ask for a serial number if at all possible before bidding. If a seller can't provide a serial number or a good excuse then stay away-it's probably either a)Stolen or b) A lot older than he's claiming.To check the age of an engine via the serial number google the make and HP then the word 'serial' or 'S/N' and you'll find a chart quite easily with years/numbers on to identify it from.For example if I wanted to know the age of a 50hp Blueband Mercury I'd google "Mercury 50hp S/N".

There ARE exceptions to this-If the motor is ex military it won't have a serial number. It WILL however have the recess on the powerhead that the alloy plate for the serial number would normally be pressed into. The recess should have the ORIGINAL PAINT in and it MUST MATCH the rest of the powerhead perfectly with no scratching or evidence of tampering. Reject the engine if tampering is evident-there is a very high probability that it's stolen. Generally the only motors you'll find like this are American Johnson/Evinrudes (which are painted Olive Drab or non-uk models like the GT150), or if an ex UK Forces motor then Mercury or Mariner-usually 40, occasionally 50hp and quite often now the Mariner 75hp 'Clamshell' PLASTIC cowl type.


Finally-last couple of points

There is no such thing as a cheap outboard over about 25hp-and very rarely such thing as a cheap outboard on Ebay. There seem to be an innumerate number of idiots willing to pay new prices for scrap. If it's cheap then you'll usually spend as much on keeping it running as you would on a better, newer engine from a private seller in a Boating magazine that'll have a higher resale value and you won't have to keep messing around with it.

Don't expect to be able to get a cheap boat and chuck a cheap outboard on it. It doesn't work like that. BOAT's acronym is Break Out Another Thousand for a very good reason. You can't do it on the cheap. In a typical 'buy a cheap boat and chuck a cheap engine on it' you'll usually pay as much for the silly little fixtures/fittings as you do for the boat itself. If you don't believe me then try it.....

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Hello to all the readers :)









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