I just purchased a 2006 150 HP 2 Stroke. Before we use it too much I thought I would change the impeller. Upon splitting the case I've come across a wire or small dia. tube that goes up into the engine. I don't know what it's for or how to disconnect it. does anyone have any ideas?

Thanks in advance,

Jim

Sounds like you are referring to the pitot tube that sends to the speedometer.

I can't find how to disconnect it so I can remove he unit. Any ideas?

Also, is it needed for engine performance? The speedo doesn't work anyway but I have MPH on the fish finder.

quote:

Originally posted by Pal:
Also, is it needed for engine performance? The speedo doesn't work anyway but I have MPH on the fish finder.

If you have GPS speed on your Sonar/MFD, you don't need the pitot tube. Do you also have an analog speedometer in the console?

If you disconnect the pitot rubber tube, just consider where that water will end up when moving at speed. I'm not sure if it would be an issue, but water is entering the lower unit through the hole and has to go somewhere.

quote:

Originally posted by Pal:
Also, is it needed for engine performance? The speedo doesn't work anyway but I have MPH on the fish finder.

Not being sure that's actually what it is I can't commit to the first.
Steve makes a great point - the tube behind dash on ours got a hairline split after 10-12 years. Thought I had a hole in the boat since I couldn't figure out why the storage compartment was SOAKED but no visible leaks. Stick your head in there at speed and it was quite a different show/fountain.

However to fix it may be as simple as cleaning out the business end of sensor tube/opening on the foot. We have to do that occasionally on a Merc I/O, and I think it's an issue on every platform, especially if run in gunky water sometimes....

quote:

Originally posted by steve495:
If you disconnect the pitot rubber tube, just consider where that water will end up when moving at speed. I'm not sure if it would be an issue, but water is entering the lower unit through the hole and has to go somewhere.

Right. You disconnect it right where it goes into the gear case. The water will go in the leading edge holes and right out where the tubing was connected. I pulled it off of my 2005 250XS and it didn't affect anything.

I do have a separate speedo on the dash. It doesn't work. All the videos I've watched show a length of tube 6 to 12 inches long but it is not connected to anything, and no one has mentioned its purpose. Mine runs up into the power head. Thanks

Jim

Then I'd pull the speedo tube. As Georgeair mentioned, you can have a problem if it is connected on the engine and not at the gauge.

Just make sure you have a good exploded diagram of the lower unit before you start taking things apart for the impeller. Also, have a friend available or a mechanical means to support the weight of the gear case. They aren't super heavy, but it's awkward working down near the ground with it. Don't mess with your gearshift lever or the connecting rods when it is disconnected or getting it lined up again is more challenging.

Good luck.

Thanks for all the help! I will be back at it soon. It never ceases to amaze me the amount of knowledge, and the willingness to share I see here every day. I hope I have been able to help people in the past like I have ben helped.

Jim

Most people leave the pilot tube in the Lower unit and just put a rubber cap on it at the back of the motor, to plug it there, where it exits at the back of the motor.

On my old 135 Opti I just folded the tube in half and put a tie strap on it. Boat didn't have a speedometer I used my GPS.