OutlawBayB

Okay-just picked up boat from MarineMax Sat AM-from de'winterizing it. Put new props on & took it to the lake.....

Speedo was saying 40 the whole time-then 30(SAT), now (SUN)
it doesn't even work!!!! The GPS said it was doing 50+.

The boat is only a 1 1/2 yrs. old-pristine cond-only 50 hours. We've only run it 2 x's before the winterization. Now, all of a sudden it doesn't work???

I know the props wouldn't do that-but is there a wire/switch something they could've "accidently" touched when dewinterizing the thing?? Anything we should be looking for?????

CigDaze

Hey,
The speedo in your boat is nothing more than a pressure guage, Similar to something you would find on an air compressor, etc(with minor differences).

It displays speeds which are measured through your outdrive pitot pickup or one that is transom-mounted.

There may be two possibilities: 1)It is clogged by debris or corrossion or 2) there is a leak somewhere in the line.

Since you do get(or did get) a reading of 40 and then down to 30, I would lean towards the leak theory.

If it is completely clogged, you would have no reading at all or if it became clogged while underway the speed would stay even when you slowed down. If it is partially clogged, the reading would be accurate, just would take a long time to equalize and the speed reading would lag behind. This happened to mine once when after doing 50mph or so and I came off plane, it took almost a minute to go down to zero. Likewise, it took the same time to come up to speed when cruising along.

Now if there is a small leak somewhere, you may get a reading up to a certain pressure, until the leak can't keep up and starts spewing out water faster. You may want to look for water leaks from under the dash, and along the path of the speedo tube. If it is not inside, then likely it is in the drive.

On the trailer, trim the drive up to the max and look under the bellows, you will see a small diameter black tube leading to a blue or yellow fitting(I don't remember) on the upper side of the cavitation plate. Sometimes the tube partially or completely slips off the fitting.

If those don't cover it and you suspect a clog, this could be really tricky to find let alone clear. You can use coat hangers, pipe cleaners and even blowing through with an air hose.

Good Luck!

CigDaze

Oh ya...
If the tube has fallen off the fitting on the outdrive, and you push it back on, it will undoubtedly fall(blow) off again. This also occurred on our boat repeatedly after the tube hardened and lost it's resiliency. You will need to wrap a tie-wrap around it to secure it.

OutlawBayB

Thanks BajaDaze! I'll make sure the "hubby" reads your instructions. Yeah, it quit working all together on Sun.
We'll let ya know!

Sydwayz

iTrader: (1)

It sounds as though you may be clogged or disconnected from the pickup tube. Depending on your manufacturers choice, you may have a transom pickup tube instead of using the one on your drive. They are more accurate, or at least as accurate as a speedo can be.

Check for disconnections from the pickup, and if that is not found to be true; disconnect the tube from the back of your speedo, and insert a compressed air fitting into it, and try to blow the debris back out the pickup. Obviously, do not try to blow the debris toward the speedo from the pickup. I have one of those cheap inflatable air-fillers, and hook it up to a compressed air hose, and can usually free any obstructions in this fashion.

I am ripping the whole thing out this year anyway, and going with a GPS speedo. It really is the way to go.

E Z TERMS

the pick up tube is probably clogged - used to happen on my old baja about every 2 weeks .............

take a 1/16 drill bit and rotate it by hand into the little hole inthe front of the lower unit........try not to push the crud in but let the drill screw its way in then pull it out...........

EZ