Air cooled Tohatsu 5 HP ? anybody any info ?

ruddles · 09 October 2008, 11:35

Hello all
Hope someone can advise here.
I have been given (Gratis) an absolutely mint Tohatsu 5 AIR COOLED outboard, vintage unknown, probably early 80´s ?.

Model, B9B

I have lowered the leg, opened the gearbox and lifted the powerhead. It is absolutely like new. Looks like a few hours use then layed up. Now reassembled. It has a water cooled exhaust by forced feed from an outlet behind the prop leading to the powerhead area, no water pump. Lovely piece of kit. Ideal for my redcrest second dinghy. (it even has forward neutral and reverse shift and beautifully buit.

What I would be very grateful for is ANY info. Have emailed Tohatsu Japan for any info with the model and serial number.

Anyone any idea of the age ? ?????

Does ANYONE know, the oil type for the mix and ratio ? (I know SOME early outboards used sae30 or similar as opposed to TCW-3).. dunno with this one. I presume 90´s in the leg gearbox too.

Also, plug gap and points gap ?. I can find no info on the emptynet at all.

Cheers n beers guys.

Rudds

ruddles · 09 October 2008, 21:46

Sorry mistake I thought the mariner 5 air cooled was the same, its not !

Locozodiac · 09 October 2008, 22:09

Quote:

Originally Posted by ruddles

Sorry mistake I thought the mariner 5 air cooled was the same, its not !

Tohatsu made the first OB-2 outboard machine in 1956, was a 2 strokes air cooled 1.5 HP, so imagine 5 HP several years latter, anyway a nice oldie relic from glorious past. Hope you find requested information at Tohatsu. Maybe they'll exchange for a nice portable 9.8 HP, "Thumbs Up"

Happy Sibbing

ruddles · 09 October 2008, 22:26

Hi Locozodiac
Nice one, I found a pic of an apparantly identical model, the Tohatsu Sea Swallow, model B9A, mine is a B9B, only difference I can see externally is mine has a twist grip throttle (posh eh !

) and the cowling on mine is blue with a white centre as opposed to this pic which is white with a blue centre

The one in the picture here is even cleaner than mine !

They made them well, and still do !.
When I get details of the oil type and mix I will take it for a spin.

Rudds

Nos4r2 · 09 October 2008, 22:53

For now,if you assume 25:1 you won't hurt it with a quick 10 minute spin. It may be 50:1-and possibly shouldn't have TCW3 oil either as it's aircooled.

Hop over to Iboats.com forums and ask in their Nissan/Tohatsu problems area.

Locozodiac · 10 October 2008, 00:57

Quote:

Originally Posted by Nos4r2

For now,if you assume 25:1 you won't hurt it with a quick 10 minute spin. It may be 50:1-and possibly shouldn't have TCW3 oil either as it's aircooled.

Hop over to Iboats.com forums and ask in their Nissan/Tohatsu problems area.

Being a 2 stroke engine definitely must use regular TCW-2- 2 strokes oil, like in air cooled motorcycles, grass cutting machines, chainsaws, etc. Would like to know what is the tech difference between TCW-3/TCW-2 oils uses, maybe (3) for use with high rpm refrigerated engines compared to (2) low rpm air cooled engines.

yorfuoj · 30 October 2008, 20:06

Oil : for safety, I would use an oil made for air-cooled 2 stroke engines, like motorbikes, scooter - not a marine oil like TCW2 or 3.
% should be 3 to 4% unless other specified

samt · 30 October 2008, 20:57

I had one of these as my first ever outboard!!! (apart from a 2hp johnson which never ran)

Lovely little thing. Used it on a 3m inflatable, for about a year. Then it died a horrible death at the start of the next season when it blew up, and cracked the engine block!!!

I'm pretty sure it was 50:1, watch for rust on the integral tank. I did have a manual for it in PDF, but its dissapeared with my old computer.

Utpost9 · 04 May 2018, 16:45

Quote:

Originally Posted by ruddles

Hello all
Hope someone can advise here.
I have been given (Gratis) an absolutely mint Tohatsu 5 AIR COOLED outboard, vintage unknown, probably early 80´s ?.

Model, B9B

I have lowered the leg, opened the gearbox and lifted the powerhead. It is absolutely like new. Looks like a few hours use then layed up. Now reassembled. It has a water cooled exhaust by forced feed from an outlet behind the prop leading to the powerhead area, no water pump. Lovely piece of kit. Ideal for my redcrest second dinghy. (it even has forward neutral and reverse shift and beautifully buit.

What I would be very grateful for is ANY info. Have emailed Tohatsu Japan for any info with the model and serial number.

Anyone any idea of the age ? ?????

Does ANYONE know, the oil type for the mix and ratio ? (I know SOME early outboards used sae30 or similar as opposed to TCW-3).. dunno with this one. I presume 90´s in the leg gearbox too.

Also, plug gap and points gap ?. I can find no info on the emptynet at all.

Cheers n beers guys.

Rudds

-----------------------------------------------------------------------
Go here https://www.tohatsu.com/tech_info/manuals.html

check under 2-stoke M 5B for internal tank
or M 5BS for external tank