Tohatsu leaking fuel

[stuey_two]

My Tohatsu 3.5hp ouboard (3 years old) has been laid up since last season. Yesterday I tried to start it - no problem, it fired up OK.
After I stopped it, I left it hanging on it's bracket with the fuel still switched on. After a few minutes fuel started to drip from the engine and only stoppped after I switched the fuel supply off.
I don't remember this happening before - is it normal, or has a fault developed, and if so have you any suggestions?

 

[jeremyshaw]

Float valve in the carb stuck or damaged? Similar thing happened to me.

 

[oldharry]

Stuck float valve.

 

[VicS]

Obviously inspect all the connections between tank and carb. Also the fuel tap itself.
The most likely thing is that the carb is flooding due to the float being stuck or the needle valve not closing beause that is stuck open or has some dirt in it. You may go back and find it has sorted itself out or it may free itself while you are dismantling it.

 

[StugeronSteve]

I had this with my new Tohatsu, last summer. I took it back to the supplier who guessed that I had been leaving the fuel tap open and gummed up the float valve. I protested my innocence and so he checked and found a cracked fuel tank, which was then replaced under warranty.

 

[tyce]

my yamaha has same problem its the float valve

 

[yoda]

Float valve stuck. Remove cowl and then carb, invert over somethintg to catch fuel / parts and remove float chamber. Clean out all the dirt etc, remove float and float valve, clean carefully with clean fuel and re-assemble. Probably one of the most common faults with small outboards and easy to resolve.

Yoda

 

[davidpbo]

As others have said, probably stuck float valve, maybe caused by fuel left in chamber. Fuel evaporates leaving oil I think.

David

 

[soulofasailor]

I guess this is a old posting, i have a 2002 and it is leaking form the float area so i will check and see if the float is stuck also
thanks

 

[BrianH]

I guess this is a old posting, i have a 2002 and it is leaking form the float area so i will check and see if the float is stuck also
thanks

Yes, it is a very old thread - but welcome to the forum.

Most of these type of fuel leaks are float chamber valves stuck open but here is a warning case I had with my Johnson 3.5 outboard, of about the same vintage as yours, which is a re-badged Tohatsu and no longer quality US manufacture that Johnson/Evinrude used to be.

It was mounted on a pushpit bracket and while sitting in the cockpit I noticed the strong smell of petrol and discovered fuel leaking copiously from the fuel tap at the side of the unit. After decanting the rest of the fuel tank contents into a container I disassembled the plastic cowling covering the fuel line to the tap assembly, removing the latter completely from the plastic tubing from the tank to the carburettor.

The tap is a simple rotating plastic moulding seating on a static section that connects to the in/out tubing, with holes in both that match up when turned with the lever pointing down. The rotating section has a spindle (a single moulding with the lever) that passes through the static section and is retained by a washer and nut – metal threaded onto the plastic spindle, with a spring spacer to apply pressure of the rotating part against the static section. The spindle had broken at the retaining nut releasing the pressure between the two sections and allowing fuel to pour through. To my knowledge there had been no impact or stress on the component, which is anyway largely protected behind the cowling.

The design is clearly at fault – the thin plastic spindle moulded with the round, rotating section that critically must be held by the spring hard against the static section to ensure no fuel escapes, with a metal nut screwed onto the plastic spindle. Not only the design seems poor, the metal parts, spring, screws and nuts, all showed rusting that suggests poor quality components.

I toured the region searching for a replacement, to no avail. The official Johnson dealer had none in stock and ordered one - delivery time at least a week. However, an obliging local mechanic took the stub of the spindle and reamed more thread on it and replaced the nut without the coil pressure spring - there was no space. By luck the pressure contact between static and rotating sections seems optimal and I didn't pick up the ordered part - it was anyway a rip-off price for such a shoddy component.

 

[soulofasailor]

Thanks for the reply and i guess i should say i did replace this calibrator kit or float assembly or whatever they call it.. i was having issues that the motor wouldn't stay running , and then found out that the spring was not even so that fixed that and now this issue . I will take it apart this weekend, i bought this motor like 3 years ago, and have messed with it for some time.. I would love to have that battery pack electric motor deal at times.. my sail boat is only 1000bls but these motors new are very expensive!