Tohatsu 70 Speedo

[Huntersbane]

I have a Tohatsu M70A2 70hp and I have been told there is a hole in the gearbox to fix the speedo pipe. Can't find mine. Any one have any idea???? I have (at the last count) purchased 4 Senders (that screw onto the transom), Plastic thing that gets ripped off all the time .

Help.

P@ul...

 

[mikewilkes]

Is it worth going to the Tohatsu dealer and asking - or am I being too simplistic???

 

[jfm]

The normal set up is there should a tiny hole in the front (sharpish) edge of the gearbox, above the propshaft but below the cavitation plate. Inside the gearbox the bottom end of a 6 inch length of 5mm ish dia plastic tube should be attached to a spigot behind this hole, so the hole runs through to the plastic tube. The top end of the plastic tube should be dangling free somewhere just above the gearbox, at the bottom of the transom clamp bracket, possibly with a stopper in it. You connect a pitot tube speedo to this end of the pipe (remove the stopper) and that's the job done. The forward speed of the boat pushes water through the gearbox hole, up tube, so compressing the air in the tube. The speedo is actually a pressure gauge, calibrated in mph. This type of speedo is instantly recognisable becuase the mph scale is non linear

BUT - I'm not sure Tohatsu had this speedo-ready set up. The other big makes did.

If you are having problems with a speedo, why not just use a GPS set?

 

[brianrunyard]

Why not use a GPS, far more accurate

 

[Huntersbane]

Well Thanks for that.

As you say ---- I Have been told that the 70A model will not have the Speedo Sender facility.

But I cant have everything.....

Cheers

P@ul... /forums/images/graemlins/crazy.gif