Logo
FULL SITE MENU

Tach Reads Too High

B

bigtoldaddy

Member
"My tachometer reads too high&

"My tachometer reads too high( it maxes out at when I get on plan and stays there) on my 97 200hp Evinrude and I know it's not the engine. It came like this when I bought the boat, so thinking it was a bad tach, I put in a brand new one and still the same thing. I know the setting on both tachs are right (6) and my mechanic says theres nothing wrong with my motor. I'm running a dual switch battery setup and all my gauges in my dash are linked together as far as the power and negitive. Am I missing something? Any help would be great. Thanks."
 
Double check your setting on t

Double check your setting on the tach and be sure it is set on 6P and NOT 6C.
 
"I'm 100% sure it's no

"I'm 100% sure it's not the prop (brand new) and I even put on the spare and same thing. Both tachs were checked on all settings and yes, it's on 6p. Could I have bought a bad second tach?"
 
so you say this has happened s

so you say this has happened since you bought the boat????
maybe at some stage someone has change the regulator rectifier at some stage and has replaced it with the wrong one and the pick up is diffrent?????
that is seriously just a stab in the dark!
 
what does your voltmeter read

what does your voltmeter read when the tach is reading too high?....if it is reading 16v or more try turning on your running lights and/or any other load you may have that draws dc off the rectifier/battery and see if tach reads right...get back to us on voltage reading..
 
"My Votage reads 13.8-14 const

"My Votage reads 13.8-14 constant. I had the motor just checked out and everything (reg/recifier) works as should. It's got to be something in the wiring or tach or my setup, I just don't know how. The tach is a new Faria but it was out of the "big lot sale" for $10 but the same was happining to the orignal tach also. Should I spend the money and get a better tach or retrace all my wiring? Thanks for any help."
 
I thought it might help if I p

I thought it might help if I put out the boat I'm running also. I have a 97 19' Proline CC with a 97 200hp Vindicator Evirude on the back. thanks.
 
does the tach read at all?at l

does the tach read at all?at low rpm?when you first start engine....i am at home and do not have a wiring diagram for that motor....lets see if someone that does can step in and help...
 
"Yes, it reads just fine at lo

"Yes, it reads just fine at low rpm. On the hose and not in gear, it reads around 1000 rpm. I don't know what it should idle at though. The tach could be wired wrong from the get go. I just put the new one same way I took it off the old one. Thanks."
 
"Don, have been reading throug

"Don, have been reading through all the posts here - if you don't mind I have a couple of questions...

First, is the tach signal coming from your main harness or is it a wire that someone has run from the engine by itself?

Second, you say it maxes out on plane. At what, 7K? 6K?

You mentioned that the prop is new, what pitch is it? I wouldn't suspect that it's "spinning" but it may be severely underpropped (maybe).

Your boat/motor combination, properly propped (19 pitch by the prop calculator) should hit in the mid to high 40's (44-48 mph) range at about 5800 rpms - to illustrate what I'm saying in the previous sentences, if you were only running a 13 pitch (for example), you would be maxing out at cruise speed...

Your idle speed sounds ok, should be about that while in neutral and drop into the 600-700 range in gear..."
 
The signal is running through

The signal is running through the main harness but it goes into the "check engine" gauge first then back up to the tach. It's a 7K tach. The prop is a Balistic 14 1/4 x 23 pitch prop and my spare is a 15x 17 pitch. Both are new. The 23 pitch runs me 53mph at WOT and the 17 pitch runs me around 40 at WOT. The tach acts the same with both props on. Thanks.
 
"Don, some of the questions he

"Don, some of the questions here may seem a little "out there", but tough to try and do a diagnosis when you don't have the engine in front of you (can't take anything for granted).

I don't know what to advise you at this point - it sounds like everything is how it "supposed to be" - you could try connecting the tach directly (bypass the check engine) - I can't think of a reason why this would make a difference, but everything else appears to be in order..."
 
I have seen similar behavior w

I have seen similar behavior when certain types of gel-batteries have been used.
What kind of batteries do You have?
 
"The batteries are just run of

"The batteries are just run of the mill marine batteries from walmart. They might be different amp sizes though. I will try running the lead wire direct to the tach and see what happens. The boat/motor runs perfect regardless of a tach, just nice to have one. thanks for all the help."
 
i think the tach is ok if it r

i think the tach is ok if it reads ok at 1000 rpm...i dont understand your battery hookup..i have had similar failures caused by batteries also...i would disconnect the dual lashup on the batteries and just hook up one..hook up the oldest one..what is the rating on that battery if it still fails?make sure the tach that is hooked up is the one that reads ok at 1000 rpm..i also would hook up a voltmeter directly to the battery and see what that reads at the failure point...take a reading before you start engine...take another at 1000 rpm after giving the battery a few minutes to recover from the cranking load..then take a reading at failure point..
 
Back
Top