Speedometer hole plugged in lower unit of 150

[<TNfisherperson>]

Hi Board users,

I have a 150 HP with the speedometer hole in the lower unit plugged and plugged good. I have tried up to 120 psi to blow it out (with the lower unit off and connected to metal fitting at that point. I have not disassembled the lower unit, I do not have a drawing or manual that tells me how this is put together.

Does anyone know how you can access this little stainless tube that is exposed on the lower unit outside that is used to sense speed?

Thanks

[<jb>]

most likely plugged from the outside....i would take a small drill bit by hand and try to clean it out,or maybe turn it with pliers...if that doesnt get it..good luck.

[<Gary Price>]

I had this problem on my 130hp.
The hole on the front face of the lower unit is only about 1/16" diamater, but the hole inside is much larger, about 1/4".
I removed the lower leg. There was a plastic adapter that the speedo tube fitted to at the top, I removed this, it just unscrews, but might be tight as it has sealant on the thread. I used various drills, bits of wire etc, to clean the vertical hole, there was all sorts of corrosion, grit, sand etc in there. Then I used a small drill to clear the front hole. Finally I used duck oil and an airline to make sure it was clear. Since I did this it has not blocked up again, it used to block up regularly.

Regards

Gary