Tach problem on 115hp inline 6

[frozenokie]

I have purchased a used boat that has a "hybrid" motor set-up. It's a 1976 1150 (115hp) skeleton and controls including guages. The power head has been updated to a 1986 model. When idling the engine, the tach sits at about 200-300 rpm. When I tap on the guage, the needle jumps a little but goeas right back to that setting. I don't know the correct way to test it. Do I need to replace the guage with one that suits the newer electronic ignition set-up for the 1986 power head? Or is it just malfunctioning?

 

[Chris1956]

Re: Tach problem on 115hp inline 6

Hey Froze, The tach for both those motors is the same. iThe tach runs off the stator(counting stator pulses). Time to check the wiring and connecions to the tach.

 

[jimg984]

Re: Tach problem on 115hp inline 6

yes tach works off stator & rectorfier rectorfier could be bad esp if the charging system is not working dont test charging system by remove battery cable

 

[hkeiner]

Re: Tach problem on 115hp inline 6

The below linked website has a tach troubleshooting guide that might be of help to you.

http://ww2.tflx.com/tech.html

 

[brybry]

Please help 115 mercury 1150

Please help 115 mercury 1150

what year is my motor?SS#4570659.please email me @ bslks0895@aol.com

 

[Deltarat]

Re: Please help 115 mercury 1150

Re: Please help 115 mercury 1150

I have a Ser. #4603471 which is a 1977 motor even though it's a 150 hp motor. However, I would assume your's is a 1977 motor.

 

[frozenokie]

Re: Tach problem on 115hp inline 6

Hey Froze, The tach for both those motors is the same. iThe tach runs off the stator(counting stator pulses). Time to check the wiring and connecions to the tach.

Hey Chris, I agree on checking the conns. That is my first task this weekend. I have replaced stator and rectifier in a '75 Merc 85HP that I rebuilt years ago when I had a similar problem, so at least I'm familiar with that procedure if I have good conns. My guess is the same as yours and I hope we're right since that is the easiest fix. I'll let ya'll know...

 

[frozenokie]

Re: Tach problem on 115hp inline 6

The below linked website has a tach troubleshooting guide that might be of help to you.

http://ww2.tflx.com/tech.html

Thanks for the link and I printed off the wiring to use as a guide while checking my conns. Thanks a mil

 

[brybry]

Please help 115 mercury 1150

Please help 115 mercury 1150

what year is my motor?SS#4570659.
I have the 17 ft bass boat with a mercury 115 hp 1150.only had it for two week and had it in the water 2X. run good intil the last time out we play/fish for a few hour and started to the dock my motor blog but clear up but before i got to the dock it shut off and was hard to start. Can only start it working the gas, so i put plugs, wires,cap,and rebuilded the fuel pump,also put a new filter on the line.same problem will not ideal and runs rough but sounds good at high rpms.SOMEONE ANYONE HELPPPPPPPP.TO TOP IT OFF DAD IS RIDING MY *** TO GO FISHING....HE DON'T TAKE NO FOR A ANSWER. I WILL BE OUT THERE WITH A 17FT PADDLE BOAT HELPPPPPP

 

[Don S]

Re: Please help 115 mercury 1150

Re: Please help 115 mercury 1150

Start a new thread with your question brybry, don't just change the subject to your own queston. This thread is about frozenokie's problem, not your not knowing the year of your motor.
Did you check the first thread in this forum?

 

[bexi]

Re: Tach problem on 115hp inline 6

might be a silly suggestion but just incase.....
is it an original tacho??
if it's an eaftermarket tacho... it might be calibrated for a 4 cylinder or 8 cylinder which will give you a false reading