Engine Tach guage

[lyle]

My engine rpm guage has been erratic the last couple of times out (definately just the guage and not the actual rpm). I have had this issue once before and fixed it by adjusting the pot screw at the back of the guage to obtain an accurate rpm. When I went to adjust the screw again the pot screw seems to have backed right out and is not attached to anything making adjustment impossible. Does anyone know if it is possible to rebuild the guage to repair the problem?

[KenKrawford]

Lyle - I don't know the answer to your question but I'd suggest calling either Seaward at (562) 699-7997 or Teleflex at (914)907-1000. Seaward makes the instrument panels on Catalinas. I'm not positive but I think the tachometer is made by Teleflex. You should be able to find the name some where on the instrument.

[lyle]

Thanks Ken. I'll give them a call

[nybor]

hi all. Hopefully I am posting this in the right forum.
I replaced my instrument cluster but note that the tach needs to be calibrated. Has anyone done this? I gave my old one away and forgot to note the "A", "B" or "C" switch position. I assume one uses a tachometer (non-contact) down at the engine (flywheel?) but other than that, no clue.

anyone out there who has done this?

thanks in advance.
dave b

[jbd3]

Just worked on mine (hull 394) at the setting was B. Hoping the fix for erratic is as simple as I've been hearing..BTW, Esperance was our home for the last 3 weeks on a 600+ mile excursion to the North Channel and back to the bay of Green Bay. Everything was flawless except the weather. Love the 350..

[nybor]

Thanks. I will switch it to "B"
Also, Tim, I will be over there sometime next week.
thanks

dave

[Richard Ad]

My tach was being temperamental and here's what I found; 1.) a poor electrical connection can effect your tach. I added a new ground wire from my instrument panel to the engine block. This fixed my tach as well as my engine thermostat accuracy. 2.) the tach was erratic when I started the engine with my shore power plugged in and "On". I now only start the engine when unplugged from shore power. Every now and then I open the instrument panel, pull the wires (one at a time) clean bare wire ends with sand paper and alcohol and replace.

[nybor]

Rats. My tach is doing something strange. It is a replacement unit, not identical to the orginal one, but new. It worked fine for maybe 10 hours. However, now when I start the engine, the tach doesn't register rpm until I advance the throttle a bit. It then indicates the correct speed for about 8 seconds, after which it drops to zero. After another brief time (seconds) it jumps back up to the original speed, stays there for the 8 seconds and off again. It does this three times then goes to zero. The only way to get it to register again is to turn off the engine and restart it. The up and down sequence then begins again.

I cleaned the contacts at the alternator and instrument panel. No joy.

Anybody had something similar to this?
thanks

dave

[leigh weiss]

Dave,
The tach gets the signal from the alternator which is controlled from and by the voltage regulator (internal or external).
Which type of regulator do you have?
If the alternator output drops (use a volt meter at the output of the alternator) when the tach goes dead then suspect the regulator.
The time delay of the tach stopping suggest to me that it is a control issue.
Do you have solar or wind chargers connected to the boat electrical system?
If you do, this may cause the alternator voltage regulator to sense a high enough voltage to shut down soon after an engine start.

[nybor]

Leigh, you are SOOOOO smart. I thought about it the way we engineers do. What is different now, compared to before - when I didn't have the problem. You guessed it, Solar (and 280+ watts to boot). I think that when my batteries are on float (seems like most of the time now), the alternator gets confused and hence the A/C out problem. So this week end, I am going to disconnect the solar, turn on the fridge to lower the battery voltage and then start the engine and see what happens.

I am almost certain what you mentioned is what is happening. On the first engine start (it took awhile to start due to the freezing cold - 77 degrees!!!!!), the batteries would discharge somewhat. The tack worked perfectly for a longer time compared to a shut off and immediate restart. Indicates the batteries were close to full after the first start and for subsequent starts.

thanks for the valuable input.

dave

[leigh weiss]

Dave,
I am not that smart, only had to figure out the same problem a few months ago. As I ran the engine with the refrig. going no problem...when it shut down the voltage rise from my solar array caused the ARS-5 voltage regulator to shut down and then no tach.
My solution is to run the power vent or other loads when motoring in the bright sun light. this keeps the voltage down.
Have fun freezing in Fl.