Speedometer help

[Thehustler]

I have a 94 caravelle ski boat I and needing help cleaning out the tube tht reads the speed. I need a way to clean it out. I have blown air from the speedometer back and nothing came out I think it's clogged in the hole on the outlive. Any suggestion please

 

[Texasmark]

Re: Speedometer help

Okaye, I am going to assume that your pickup is like my Merc OB in that in the leading edge of the lower unit is a hole and that leads to a hose barb where a hose is attached and takes the water pressure to the meter.

I would remove/cut off the hose at the end of the barb and then remove the barb. Then with a piece of wire, of suitable size, I would probe from the rear first, then pressurized water, then from the front and pressurized water till I got it cleared. Then taking the wire again, I would roll it around where it would scrub the sides of the hole to help remove foreign debris. A shot of penetrating oil in both directions would help. That's how I'd do it.

Mark

 

[cr2k]

Re: Speedometer help

Could be anywhere...What are you working on, not the boat the engine/drive?

 

[Texasmark]

Re: Speedometer help

I misread the post yesterday. I read him to say outdrive and he said outline. I agree it could be anywhere and a little air pressure in the hose at the rear of the gauge is a good place to start. Then put it on the gauge momentarily and look for deflection to ensure it works. I'd only use about 10 psig on the gauge and not more than 25 on the line.

Mark

 

[Thehustler]

Re: Speedometer help

Ok I think I have it narrowed down to the outdrive. I unhooked the hose on both ends and blew air through it and it was clear the hooked the hose back to speedometer and blew a little air and the needle moved. So I am thinking its clogged where it pickes up the water pressure on the outdrive. I have taken a safety pin and a straight pin and got some stuff out but can't seem to get it all out I have even tried a wire hanger. I have blown air in both direction and nothing comes out. Is there a way to take it apart or do I have to disassemble the whole lower outdrive?? This may b a dumb question but I am just not sure.

 

[UncleWillie]

Re: Speedometer help

The internals of the Pitot are all extremely accessible once you split the lower outdrive off.
This is an area that should be inspected/cleaned whenever changing the impeller.

When was the last time the impeller and gear lube were changed?
It might be a good time to do Both now!

You do not need to "Disassemble the whole lower outdrive", But you do need to remove it to get access.
(Merc Alpha Assumed.)

 

[Thehustler]

Re: Speedometer help

Not sure i just got the boat in April the guy put a new Motor in it last winter so he may have done tht then but not sure. Should I Chang them or wait till I winterize it??

 

[Bryant233]

Re: Speedometer help

Mine get clogged once or twice a season. I use a 1/8" drill bit that is 5 inches long that I have glued to a file handle. It works well. The stuff really gets stuck in there. You will know you have it clean when some water comes out.

 

[UncleWillie]

Re: Speedometer help

Not sure i just got the boat in April the guy put a new Motor in it last winter so he may have done them then but not sure. Should I Change them or wait till I winterize it??

Replacing the motor does not necessarily include maintenance on the outdrive.

The season is almost over so another 2-3 months will not make a huge difference.
The outdrive should be removed and inspected yearly.
The gear lube is changed every 100 hours or at least annually.
The impeller can be inspected and reused if it in good condition. Many last 2-3 years.

If you can't get the Speedo Tube clear, dropping the drive will be needed.
Or just live without it for a while.
You will need to drain the gear lube to split the case.

A Turkey Baster on a garden hose may help in getting some high speed water in there to break up the clog.

Still assuming you have a Merc ALPHA ... This is the spot in case you are uncertain.