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Best small outboard engine Tohatsu 2.5 (De-Restricted)

lee

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Here's my de-restriction of a 2.5hp Tohatsu outboard.

The 2 stroke Tohatsu 2.5 and 3.5hp outboards use no longer available and haven't been for years due to EU restrictions in place, now they are replaced with 4 stroke versions, like many I prefer the 2 old stroke versions, smaller, more reliable and more torquey.

People have been buying up the 3.5hp for the last few years and its hard to find a good one now. People tend to not bother with the 2.5hp because they want more power so the buy the 3.5hp ones, the problem now is that the 3.5hp ones that do come up for sale are most often well used as they are being used as everyday all day engines were the 2.5hp ones that come up have generally only been used as tender engines to larger boats, I picked up a as new 2.5hp yesterday with only 5 hours on it ;) so I've de-restricted it back up to 3.5hp.

The 2.5hp Tohatsu is a restricted 3.5hp engine, The block, valves, head and carburettor and jets are all the same on both models, 2.5hp is restricted by a larger carburettor intake that only allows half opening this can be removed and cut down to allow full opening. You also have to cut the plastic on the throttle cover to allow the throttle to be pushed right pass the rabbit.

The other difference between the engines is that they made the 2.5hp direct drive with no gearbox, this makes it lighter and less to go wrong.

So if you want a good little engine for your small boat or canoe, keep away from the abused 3.5hp ones and de-restrict a 2.5hp ;)

All 2.5hp Mercury, mariner engines are restricted 3.5hp as well as, some only have a restricting plate with a smaller hole fitted inbetween the carburettor and inlet, simply remove the carburettor and removed the plate, others like the Tohatsu below take a bit longer (10 mins) to de-restrict.

To to de-restrict the Tohatsu 2.5hp outboard.

Restricted:

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Intake valve modified. (About 8mm cut off)
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Valve refitted, carburettor now fully opens
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Longer cut made on throttle cover to allow throttle to go right open
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Mint engine ;)
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Running at slowest setting ;)
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Video on de-restricting the Tohatsu 2.5hp with before and after power test. (not me)

 

lee

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The tohatsu, Mercury and mariner 2.5hp outboards are all the same engine re badged (all made by tohatsu)
 

lee

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This is a good set up and easy to mod joe, running 2 x 3.5hp should get you up on the plane and the security of knowing you have 2 outboards so you will always get back if one fails ;)

Think I might have to try this for Josh's new boat set up his getting ;)


 

lee

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Note* you may have to slightly adjust your idle screw after the mod for a correct idle speed.
 

Ark79

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Nice write up lee....Not something am into m8 but a do like mods on things:thumbsup:..a have on the other hand been toying with the thought on getting a canoe for the loch near me for fitness and fishing...
 

lee

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Getting on the water is a lot of fun mark, with a canoe your bush camping experiences and options of quite locations and fishing increase dramatically, a little outboard on a canoe will let you travel miles effortlessly ;)
 

Ark79

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Av been toying with the idea for a wile now. That's a good point it will open up more options for camping fishing and a good way of staying fit. A think a will get one now lol
 

lee

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https://www.ebay.co.uk/itm/261432325966



Somthing like this lee...just to start with
Go for a wooden or fibreglass canoe with a transom back to take a motor but they are rare to find, you can always add a motor mount to any canoe that doesn't have a transom (video below) you only need a small engine for lakes a little 2hp would do well

Get a proper canoe mark as the kids and misses will defenatly wanna join you :)


 

lee

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You can also get more power from these 3.5hp outboards by fitting a improved propeller (high thrust) this is not a mod I've done yet but may look into it ;)
 
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