Yamaha 90 Lower Unit

[tpark1]

Greetings, I recently purchased a 2001 (I think) Yamaha 90 HP outboard. As I was going through it I noticed two things that I don't understand. First, there is a small diamater tube that runs from the boatside of the lower unit up over the hydraylic tilt motor and cylinders and comes out near the steering tube on the front of the engine and is plugged off. The tube has been smashed (improper routing?) in the hydraulic cylinder area. Upon removing the lower unit plugs quite a bit of water escaped out the lower hole. Baring a pressure test, is there any possibility the water could have entered through the broken tube (it is broken below the water line). Also, on the left side of the cylinder head (standing at the rear and looking forward) there is a brass bolt with a hollow center it a position where a head bolt would go. The hollow center drips a drop of water every minute or so when I am running the engine on the hose in the driveway. Any ideas what this is and how I can fix the drip? I am assuming it may be a receptor for a temperature sensor that stayed with the old boat.

Many thanks,

Thomas

 

[mikesea]

Re: Yamaha 90 Lower Unit

The water did not come from the hose.That hose is for use with an optional water pressure guage that can be installed in the dash.Unfortunatly,that water means bad news.You dont want water in your gear oil and I hope there was oil in ther too.If not your lower unit will need rebuilding.If there is oil too,then you need to get it pressure checked to locate and seal the leak,it WILL get worse.The part on the head.I believe you are refering to a heat sensor that is likely broke.The piece can b removed and a plug for replacement.That to I beleve is an optional senson.You should see another sensor that has a wire that comes out of the head on the top.I suggest you bring your issues ,especially the lower unit water problem to be checked asap.Especially if no oil came out.as long as some oild was in there ,your parts probably have some protection from rust.You dont want the lower unit to be empty after water discovery.

 

[rcmickey]

Re: Yamaha 90 Lower Unit

I know this is an old post but I.m hoping you guys can help me. I have an 89 Yammy 90HP. I want to change the lower end lube but I only have one oil screw. Its labled oil level. My Johnson had two, one lower than the other, so you could pump it in the lower hole and the air comes out the top one. How do I get oil in their without air bubbles?