1987 Yamaha 150 lower unit question

[PerchJerker]

Hi Guys, new to the forum. I've stumbled into a small offshore boat and am in the process of going through the engine to make sure she's water ready. The boat had been sitting awhile so I decided to replace the water pump and all the seals in the lower unit just to be safe. When I removed the lower unit, there was a hose that connects to a nipple right near the splined shifter linkage on the foot. The hose was broke and the upper half missing. I've bought a replacement but have no clue where this hose goes. All of the online drawings aren't much help.

I've always owned OMC engines and they don't have this hose. Any help would be greatly appreciated. It's a long shaft engine if that makes a difference.

[99yam40]

only hose from lower that I know of it for speed o meter.
if you do not need or use just plug it off

[Jason2tpa]

If the hose you're speaking of looks and is located as is pictured below with red arrow, 99yam is correct. Speedometer tube. The adaptor connecting the lower unit tube to midsection tube is pictured below.

If the midsection hose was missing on your engine (the "upper" one) then I'd assume the previous owner pulled it out. The speed tube runs from your speedometer gauge to the connection made at the junction of midsection and lower unit.

Personally I've never fed one of those tubes down the engine, so maybe those who have can guide you on the best way.

[TownsendsFJR1300]

It is the speedometer tube. On the leading edge of you LU, there's a VERY SMALL ptiot hole that allows water in (and water pressure for the gauge).

Should you want to use the Yamaha speedometer, I would first check to see if the hole is even OPEN. They tend to clog up, especially if not flushed. Putting water to either end to see if it comes out. A small "V" cut garden hose end works well over the leading edge.

Should it be clogged and you attempt to use a drill bit, do it by hand as it's REAL easy to bust that tiny bit off in there.

My newer 150, the hose run's down the middle of the VERTICAL steering tube.

The older engine probably has a connector visible / accessible in the mid-section. You'll see the shifter shaft.

I'd check to see if the old hose is still there, (as pictured above) coming out the engine cowl (with the rest of the wiring/cables).

I've replaced my line once, not bad to do, sneak it down from the top(where it's the tightest).


Once it's working:

http://www.yamahaoutboardparts.com/f...g-th23159.html





.

[PerchJerker]

Thanks guys, I'll probably just fish another hose through the mid section and use with an aftermarket speedo to keep from having to drill holes in the hull for another sending unit.

I really appreciate all of the replies. Happy boating everyone!

[99yam40]

GPS will give speed also and will not plug up