Yamaha 150 speedo

[Mac3]

I have the misfortune to be a handyman a pal of mine has asked me to check the speedo on his 86 yam 150, it's no go. I see one connector, looks like a tube to me, going to the display can anyone give me a quick overview on the theory of operation. If it is a tube I imagine its clogged so I'll go from there.
If it's electric I'll probably work that through too.
cheers
David

 

[gsyfishy]

Re: Yamaha 150 speedo

There should be a plastic sensor on the transom, this has a wheel on it that sends a pressure signal through said tube, if this wheel is frozen or the tube is clogged or split (broken) it will not send enough pressure to make speedo work.

 

[gcboat]

Re: Yamaha 150 speedo

There is also another type of transom attachment that looks like a shark's fin.
Made of plastic it can break or get clogged really easy. As gsyfishy mentioned your connecting tube should be checked for any cuts or tears as well. You can use windshield washer tubing as a replacement.

 

[Mac3]

Re: Yamaha 150 speedo

Thanks guys, this one is the wheel type, I wasn't sure whether it was electrical or water pressure. I reckon the tube is blocked I had the same problem on my Johnson 150 with the water gauge and replaced it with said w/w tube. The is so much knowledge on this site I feel a little guilty always taking and never giving as I don't have a lot to give!
cheers
David