georges

How do I troubleshoot my inoperative Gaffrig speedo and water temp gauges? Neither one of them works. Don't want to run out and just buy new gauges not knowing what the problem is.
Also, can anyone tell me what kind of speeds equal 2500, 3500 and 4500 rpms, turning a Mirage 23 prop?

Stormrider

Sorry, I know..4000RPM = 50MPH and thats gps, although my speedo is accurate at that speed.

MIAMIBOYZ

George with zero slip here are the numbers, you need to divide a percent from your actual mph to the true table and that gets your slip actual %. A 10 % slip or lower is ideal for these boats performance, anyhthing higher will get you in trouble.

2500 rpm 36.30 mph
3500 rpm 50.82 mph
4500 rpm 65.34 mph

As far as your gauges, you might have a loose ground wire somewhere, get it checked, the rigging in that boat was new and I know the wires are not the problem. Good luck George and be carefull out their.


Albert

georges

Thanks,
I am just learning how to handle this thing. I saw 3500 rpm the other day, my wife was with me and I could see she was getting a little uncomfortable, so I backed off and brought her back home safely!
I know this ain't squat for you big guns out there, but this is my first time, so please.....be gentle with me!

MIAMIBOYZ

Now George you don`t want to get your first mate mad, forget about WOT and cruise around showing off Orange.

Stormrider

George, run around 3000-3200rpm for a while(35-40mph).
Don't freak her out. That would not be good.
Remember, you are driving something similar to a shelby cobra. Just the idea of being in the passenger seat can make some uncomfortable.

georges

Hmmm.....Shelby Cobra, I like that comparison.

Albert,
do you know the history of Orange?

Griff

More than likely its the sensor on the engine for the water temp guage or maybe a wiring short at the sensor or behind the dash. If you have a merc engine, you can test the sensors with an ohm meter.
As far as the speedo, it is mechanical and uses water pressure to activate it, assuming its not a GPS speedo. The water either comes in a hole on the drive or in a transom mounted pick up tube. The pick up is probably plugged. You can test the guage by disconnecting the tube on the back of the speedo and blowing some compressed air into it. If the needle moves with air, then its plugged in the line or the pick up.

MIAMIBOYZ

No I don`t George..............

georges

Thanks Griff, it is a liquid filled speedo, I'll try that.