By using the optical tachometer I determined that my boat's tachometer gauge was actually showing higher than than the true engine RPM's (by quite a bit). My question is how do I adjust the tachometer on the engine gauge?
I removed the gauge panel cover and gained access to the rear of the tachometer. I was expecting to see an access hole for a screw that could be turned...I did not see that.
I found two access ports....one was for the tach light bulb and the other was a 4 position switch with each position either in the on or off position. My position #2 was "on" and positions #1,3 and 4 were "off". Can anyone help me from here?
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Stephen Kruse
Kruse Control #1428
1995 C-36 MKII SR/WK
Lake Lanier, Ga.
Stephen, I'm about to attempt the same adjustment. When I had the engine pod open the other day, I noticed a hole in the back of the tach. And in that hole, there appeared to be a potentiometer available to adjust.
I believe this has been written up in our Maintenance library. Have you looked there for an article on the topic?
Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
Larry,
I had already checked the article in the "technical maintenance" section and searched the archives. Others have referenced a screw for the adjustment and you would use a small jewelers screwdriver to adjust the gauge. I didn't find that on the rear of my gauge. I'll try to post a picture of my tach.
Stephen Kruse
Kruse Control #1428
1995 C-36 MKII SR/WK
Lake Lanier, Ga.
here's a picture....I may be wrong, but it seemed that access hole "on top" was an on/off knob switch for the bulb and did not adjust the tach RPM. The access towards the "bottom" is the 4 position switch and measures approx 1/4" x 1"
Stephen Kruse
Kruse Control #1428
1995 C-36 MKII SR/WK
Lake Lanier, Ga.
Well, maybe your tach doesn't have an adjustment. It's a small hole in the back of the tach, and "CAL" is embossed in the plastic case beneath the hole.
See photo.
Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
I see part of the "CAL" appearing in your photo. It's just near what appears to be a small piece of blue tape, beneath the metal bracket, right side of your photo.
Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
Thanks Larry, I believe you are right! I'll check it out next time at the boat...hopefully this weekend.
Stephen Kruse
Kruse Control #1428
1995 C-36 MKII SR/WK
Lake Lanier, Ga.
Steve & Larry:
Try the C36 Owner's Encyclopedia under Engine: M25 & M35/Alternators & Regulators/Tachometer Dip Switch Settings for the calibration procedure.
Tom & Janis Grover
C36 #0949
SR/WK, M25XP
Midland, ON
Just a question here. Who knows when they switched over to a pot adjustment instead of the dip switches. As I have about 8 dip switches that I have to set in order to get it close. I have the file that tells how to set it but it is not as easy as the pot adjustment.
Randy
Randy Sherwood
Mutualfun 1990 # 1057
T/R W/K M35a
Home. Charlotte, Mi.
Boat. St Augustine,Fl.
Randy, I'd bet it is hard to say. CY usually used material up and then bought new truckloads. And skippers could well have changed out older instruments sometime during their ownership.
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
Update....I made it back to the boat and adjusted the tachometer. Larry was correct that my calibration hole was mostly covered by some tape and "hidden" behind a mounting bracket.
Before the adjustment, I borrowed the club's optical tach and determined that my tach gauge was consistently off (high) by 450RPM in the 2,000 - 3,000 range. Now my tach is within 50 RPM from 900 - 2,800 range. All in all, it was a simple and effective fix.
Stephen Kruse
Kruse Control #1428
1995 C-36 MKII SR/WK
Lake Lanier, Ga.