Jump to content
  • GUESTS

    If you want access to members only forums on HSO, you will gain access only when you Sign-in or Sign-Up .

    This box will disappear once you are signed in as a member. ?

96 mercury 75hp rpm problems


fishingstar

Recommended Posts

I took out my boat for test run today and found a new problem. The tac was running about 1000 rpm high.

At idle it's 1200 and full throttle it will max the tac 6000 normal max is 5300.

The motor seems to run fine but last time out I had problems with the oil level sensor. the last time out it 

was very rough I was thinking that was the cause of the float to sink causing the alarm to sound. It has not 

came on again. Who thinks these are related?

      

Edited by fishingstar
Link to comment
Share on other sites

Sounds like you may be having some electrical issues. When you turn the key to on "without" starting the motor. Where is the tac sitting then. I have a 95' StarCraft with a 75 Merc and every once in a while the tac will just start jumping around but it's not the motor because it never picks up pitch and when I turn the key off some times the tac will shut off sitting at 1000.  I know that tac is old and going and it is not the motor. 

Link to comment
Share on other sites

58 minutes ago, fishingstar said:

Have you had oil alarm problems?

None here as well.

I would rather see the tac jump around as long as I can hear the motor running.  But oil alarms. :(

Link to comment
Share on other sites

The wiring in the some of the older boats are dump. My dads got a 1988 crestliner and here about 8-10 years that stupid alarm would always be going off brought it in and said just do premix they took out the whole oil tank and he's done oil premix ever since works like a champ. This is a evirude 60 VRO. Just my 2 cents. If I were you that's what i would be a bit of a hassle but saves some worry.

Link to comment
Share on other sites

29 minutes ago, fishingstar said:

The boat is a 97 lund pro sport. could not see any wiring issues.

that vintage of a mercury motor  96 is known to have the float get saturated with oil

and sink setting the alarm off. I think i'm good to go for the weekend  

 

Is the float cork?  Guess I never really looked at mine because I keep it topped off most of the time. I hate alarms!! :(

Link to comment
Share on other sites

Now you got me worried and thinking about it! :angry:

 

Got this off a Merc repair site about the 75hp.  Were you getting beeping or just a continuous alarm?

 

"The oil tank fault is normally not a continuous beep. Continuous beep is often the oil/overheat module that combines the two sensors into one wire. Oil tank fault(blue wires) is a beep beep beep...
Serial, year and model number will get the proper drawing and confirm this." 

 

Here's a video where a guy cuts his tank in half to see how the alarm float works.

 

 

Edited by leech~~
Link to comment
Share on other sites

well my alarm started going off Saturday morning. I stopped and unplugged the low oil alarm didn't help. but after sitting for two hours it didn't alarm. It didn't come back on until sunday afternoon when we were going to leave sitting in shallow water 3 feet

it started to beep then after 1/4 mile the alarms tone started to change then went away.

I had other things going on also. deep finder quit working, timer for the aerator started to buzz.

after work started looking at wiring. I found the ground strip and wires all corroded and the fuss holder was green.

I cant see that the corrosion has any thing to do with the alarm. I think they are a separate system.      

Link to comment
Share on other sites

Join the conversation

You can post now ↓↓↓ or ask your question and then register. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and Privacy Policy. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.