Cruisers Forum

  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
Thread Tools Search this Thread Rate Thread Display Modes
Old 19-04-2012, 07:01   #1
Registered User

Join Date: Jul 2011
Location: Cairns Australia
Boat: W Boden 56' Timber trawler
Posts: 6
GM 8v71 Tacho problem

I have a Detroit 8v 71 2 stroke diesel which runs well. The issue I have is the tacho under reads the engine revs. At full noise, it shows about 1400 rpm and the needle appears very sluggish. I would like to check the connections but I can only locate 1 wire which runs off the alternator. Does anyone know where the other wire is connected to? I guess if the other connection is fine then I have a dodgy tacho.
Any advise would be greatly appreciated.
Spongebob is offline   Reply With Quote
Old 19-04-2012, 07:43   #2
Senior Cruiser
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,837
Images: 241
Re: GM 8v71 Tacho problem

Your tachometer probably has a “range selector switch”, which adjusts for differing numbers of flywheel teeth, and must match your flywheel.
The Proximity Sensor (on Bell housing) may have a Grey wire, which goes to the Sender Terminal, and a Black wire which goes to the Ground Terminal (both on Tach’).
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"

GordMay is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Advertise Here

All times are GMT -7. The time now is 15:00.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.