RPM limiter Mercury115

[nfrnkish]

I had a no-fire situation which was resolved when the second kill wire going from the RPM limiter to the CDI unit was disconnected. The engine now starts better than it ever did (in my hands). <br /><br />I think there was a problem with this for a long time - the warning control unit is wired through the limiter, and the buzzer behind the dash had been previously disconnected. Also the tacho no longer works. <br /><br />Unfortunetly, I can't find the RPM limiter on the Mercury Parts Express parts diagram for my engine (1995 Mercury 115 HP, 4 cylinder 2 stroke). Neither can I reconcile the tacho feed (from my boats wiring diagram) to the engine harness connector and the engines electrics.<br /><br />Do I have a problem with the RPM limiter or is the tacho voltage too high and it thinks that the engine is over-revving? If the RPM limiter is good, but it's receiving too high a Tacho voltage would this mean the the CDI unit is duff? Where does the tacho feed come from?<br /><br />Answers to any and all questions would be gratefully received.

 

[Al Kungel]

Re: RPM limiter Mercury115

I have the same motor and also had the no start problem a couple of years ago. The mechanic that looked at the motor at that time diagnosed the problem as the rev limiter and he disconnected one of the wires until I could install the new rev limiter. I now have again the no start problem and am thinking that the rev limiter is again not functioning.
Unfortunately, I have forgotten which wire that the mechanic disconnected - so, does any one know which wire I should disconnect.
Thanks

 

[phatmanmike]

Re: RPM limiter Mercury115

you dont have rev limiters.

you have a "mercury switch" that could go bad and short out/ kill your ignition.

you also have a ignition advance module, that automatically advances your timing if the rpms get too low. this too could go faulty.