tachometer/revised

where does the tach connect to the powerhead. i installed a tach only to find out it is not connected on the powerhead side of the electrical block mounted inside the engine cowling. sure could use this info.
thanks
1990/90hp/outboard/1991 riviera cruiser pontoon

Re: tachometer

Re: tachometer

Sure could use info on brand, year and horsepower. Tach connection varies with each.

Re: tachometer/revised

Purple wire in the cable connects to tach signal terminal. Purple wire other end connects to purple on engine terminal board at exhaust cover. This SHOULD be the second terminal screw down from the top of the terminal strip and should be next below yellow. NOT COUNTING THE STRIP MOUNTING SCREW. The wire on the other side of the terminal in the engine harness will either be purple or grey. It connects to one AC terminal on the rectifier. There should be a decal on the exhaust cover showing the cable connections.From top: Yellow, Purple, White, Green, Orange, Red, Blue, Black. Blue is jumped to Black

If your control box has the ignition switch in it and has a smaller cable running from it to under the dash, this cable will have red, black, purple or blue, and orange wires in it Red is power (12 volts) Black is ground, Orange is overheat, and Blue is tach signal. DO NOT MISTAKE THIS BLUE FOR THE ENGINE CABLE BLUE. Engine cable blue and white wires are for stop circuit.

Re: tachometer/revised

thank you for responding,the rectifier on my engine may be aftermarket or replacement it has three wires red is center black to either side .everything back to the to the tach is ok .do i just pick a black wire and see which one works?

Re: tachometer/revised

OOOh! That's the Mercury three terminal rectifier. This may be a retrofit rectifier to replace the original one. I am not too sure about it. However--The alternator under the flywheel is AC current. there will be either 1 or 2 wires (probably the black ones) coming from it to the rectifier. Choose one and connect to that terminal. Red is almost always positive voltage and you can be reasonably certain that the red wire goes into the harness then down to a connection to ultimately charge the battery. So you definitely do not want to use red.

Re: tachometer/revised

thanks for all the info i am going to be where the boat is at this weekend.
the boat is at the colorado river and i live two hundred miles away so can only enjoy on weekends or time off. put a new prop on last time i was there and need to know what kind of rpm i'm getting out of it. came with a 14/10that was pretty dinged up and found a 14/11 replacement.would like a little more top end but don't want to take all day to get there. knowing what range my rpm's are will help.
thanks again
ted

Re: tachometer/revised

Are you sure on the prop size. I'm thinking you meant 10 X 14 since diameter always is given first. But on the second prop you called it 14 X11. Is the prop diameter really 14 inches? The bigger engines only swing a 13 to 13 1/2 inch diameter props.

Most of the 50 hp props I have seen were actually 10 3/8 inch to 10 1/2 inch diameter three blades. So they may be calling one of these an 11

Re: tachometer/revised

i'll be there tomorrow early. got the day off. will double check but am pretty sure those numbers are what was on the prop.could it be it's13 1/2 and being called 14