User Tag List
Results 1 to 5 of 5
Thread: Tach went screwy
-
10-17-2018, 06:38 PM #16000 RPM
- Join Date
- Aug 2015
- Location
- Southeast
- Posts
- 1,068
- Thanks (Given)
- 134
- Thanks (Received)
- 79
- Likes (Given)
- 48
- Likes (Received)
- 614
- Mentioned
- 1 Post(s)
- Tagged
- 0 Thread(s)
Tach went screwy
Just mounted a 300 Promax to my hull. Yes, it drinks gas as everyone told me it would...
Anyhow, first time out, the tach worked well. Reading 5500 or so at 80-85 mph with a 32 prop and 1.75 gear case. 4k was bout 50mph if I recall correctly.
Second time out, 4k is 40mph and saw over 6k rpm at 70-75. Tach jumped around some. Motor should redline at 6200 or so and should be doing mid 90's over 6k rpm so something has gone wrong.
Anything I should try before I assume the tach lost it's mind and replace it?
-
10-17-2018, 06:41 PM #2
twist the dial on the back that has the pole positions back and forth a couple times than set it back to what it was on. This often fixes an errant tach. JMO
-
DangerNewb thanked for this postDave Strong liked this post
-
10-17-2018, 06:54 PM #36000 RPM
- Join Date
- Aug 2015
- Location
- Southeast
- Posts
- 1,068
- Thanks (Given)
- 134
- Thanks (Received)
- 79
- Likes (Given)
- 48
- Likes (Received)
- 614
- Mentioned
- 1 Post(s)
- Tagged
- 0 Thread(s)
Thanks. I'll give it a try. Will take my phone with me in case I need to call for help extracting myself out from under the dash. Or bite the bullet and remove one of the seats from the sliding mount. Not much room in my little rig.
-
10-18-2018, 05:14 AM #4
It probably has gone into shock with the 300....JK
Also make sure you have 12+V, your wires are tight especially ground and harness connection at motor.
BTW, they do drink at WOT, mid range should not terrible for 300.
-
DangerNewb thanked for this postDave Strong liked this post
-
10-30-2018, 03:16 AM #5
if it's anything like the older motors the grey wire at the voltage regulator/rectifier is your tach signal... bad reg can make the tach signal go nuts... but yeah sorry I got no idea if your 3L is remotely similar!
Similar Threads
-
'96 Merc 200 EFI Screwy Tach
By Hydrasports205 in forum Technical DiscussionReplies: 0Last Post: 07-18-2016, 01:42 PM -
Tach died- any way to test signal to tach with volt meter?
By CircleHook in forum Technical DiscussionReplies: 12Last Post: 09-14-2014, 05:49 AM -
Inboard tach vrs. outboard tach
By FULLTHROTLE in forum Technical DiscussionReplies: 2Last Post: 10-07-2005, 05:02 PM -
Tach connections for Gaffrig tach/1500XS
By XSRaveau in forum Technical DiscussionReplies: 8Last Post: 07-07-2002, 12:02 PM -
Tach Recall on Merc Tach
By Craig Knight in forum Technical DiscussionReplies: 2Last Post: 06-02-2001, 10:46 PM