Adding a telltale on my 40 hp tohatsu

Ive got a 40 hp tohatsu that has no telltale it spits water out the exhaust ports I want to add a telltale anyone know where I need to drill and tap a hole on the motor pictures would be helpful

I'm guessing Pappy will know and possibly a few others but it might be helpful if you posted close up pics of both sides with the cover off. Then they could use your pics to tell you where.

Ok heres the inside View attachment 1View attachment 2

- interesting post -

I also want to do this to my 50hp Chrysler Force outboard with the same exhaust system.
I just feel very uncomfortable (untrusting, really) of not seeing the pee stream.
On my 25hp Johnson, I routed a 1/4" clear tube from the telltale on the motor up to the
steering wheel side so I can actually put my hand on the pee stream to feel the warm water and also
to SEE IT with my own eyes is a comfortable feeling to see the water pump functioning properly.

This is coming from someone that has had TWO (2) motors destroyed by a bad water pump.


good question and :WELCOME: to Tin Boats.

Okay, what I do on an engine that I do not know like the back of my hand is to pick a spot on the exhaust cover. How I pick the spot is to look up a picture of the gasket and see where the water passages are. I can verify by starting the engine and feeling the colder spots on the cover.
Drill in for a 1/8" pipe thread and install a plastic overboard indicator nipple from a Johnson/Evinrude product. They are inexpensive and non-corrosive. Route the hose over the top of the block/cylinder head so that you know the pump is building enough pressure to completely fill the powerhead.
Drill through the lower motor pan and either install the correct fitting there as well or drill a touch small so it will trap the hose.

Barefoot_Johnny said:

so I can actually put my hand on the pee stream to feel the warm water and also
to SEE IT with my own eyes is a comfortable feeling

Click to expand...

Jeeze man, this is a family site!

I added a pisser for my '68 Evinrude 60hp.

Like Pappy said...

This is what you'll need...


Choose a location (I chose the cylinder water jacket)...


Drill and tap (mind your depth)...


Install water connection and hose...


Prep lower cowl for indicator outlet...


Complete install...

Im going to take a picture up on top and see if y'all think it would be a good place to drill and tap thanks for yalls help I tried to ask this question on iboats and I got a bunch of smart alleck answers so THANKS A BUNCH

Very good presentation SumDum !!!
Pappy, I thought about drilling into the water jacket as you describe
AFTER removing the cover and have a new gasket on hand to put it back.
I think it would be very advisable never to drill into a motor head if
there is any chance the metal chips can fall into the inside. That part scares me.

Thanks for relieving some of the "fear factor".

There is no part of the water jacket that is open to the "inside" of an engine.....think about it. Plus, when started up there is an automatic flushing feature for the chips!

Well here is where I put itView attachment 1

I would make sure I placed it in the water feed before the thermostat like all manufactures do. That way you get the stream/indicator upon start up. Not only after the engine is warmed and the thermostat opens.

I chose this location on the water jacket due to some reading I had done for this motor. From what I read these motors could develop an air pocket at the top there and run hot. With the tell-tale source at this location all air would bleed out. Is the air pocket real, I dunno.

you can drill the thermostat housing and screw a plastic hose 90 in it
you can buy a used housing to do that with a friend did that to his hatsu

Barefoot_Johnny said:

Very good presentation SumDum !!!
Pappy, I thought about drilling into the water jacket as you describe
AFTER removing the cover and have a new gasket on hand to put it back.
I think it would be very advisable never to drill into a motor head if
there is any chance the metal chips can fall into the inside. That part scares me.

Thanks for relieving some of the "fear factor".

Click to expand...

You can also coat the drill bit with thick grease before drilling, chips will stick to it. But Pappy is right, the chips will flush right out of it.