changed tach won't start now on the lake now

[lostriver]

2001 merccruiser 8 cly 5 liter carb. motor

Does anyone know if changing the tach would effect starting. All i did was change the tach and now the boat will not start. Seems like a no fire situation.

voltage readings to each tach post would be helpful.

Any ideas would be great Thanks

 

[Bt Doctur]

Re: changed tach won't start now on the lake now

Try disconnecting all the wires and see if it will start.
most tachs have 12v power, ground, signal lead from coil
ground the sig lead and you have no spark