erratic revs
 

anyone suggest an issue with my 4.3L?
basically starts fine and sometimes revs nicely in all throttle positions in and out of gear. Usually at some point though the revs will start dropping and sometimes rising without my input.
When in gear i will have to almost pop it out of gear to and rev the engine to overcome the issue. Even when idling with a warm engine it will behave, and then suddenly drop down to just above 500rpm instead of around 800 rpm. Last season it was fine and this issue has only occurred in the last few weeks when boat was launched for the first time.
Just to add i removed and checked the plugs and they all looked good. Also took the distributor cap off and cleaned up the terminals as there was a small amount of corrosion.

Any advice?

Cheers guys

Lewy

Re: erratic revs
 

Just to add i discovered the issue, and it was a loose cable on the battery. Tightened it up properly and that seemed to resolve the issue.......for the time being

Re: erratic revs
 

Just to add 2 years on it happened again yesterday! It might be an earthing issue with a faulty or corroded cable. On the 182 model does anyone know where all the earth terminals are?

Re: erratic revs
 

I believe most of the ground cables are located on the inside of the stern just behind the battery. At least that is where mine is. Here's a quick & easy wiring diagram from 1996 that would still be applicable for your boat;

Re: erratic revs
 

thanks Mikey, very useful.
Are there earth points on the engine too, do you think?
Mines a mercruiser 4.3L
Forgive my ignorance on these matters.....

Re: erratic revs
 

Merc typically installs studs on each side of the bell housing on the rear of the engine block. Just follow the large gauge black wires from the battery.

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Re: erratic revs
 

Thanks Steve, i'll check those too.
is it possible the battery isolator switch might also cause issues?
I say that because i had one day of faultless engine issues to the next time erratic behavior again.
The only thing in between was turning the battery switch off and on again....
thanks for the help