Why does my tach jump at high RPM?

Why does my tach jump at high RPM?

When it happens at idle, the motor lopes/lunges really bad. At higher rpm it doesn’t seem to effect running. It seems to do it more often on really hot days. Any ideas? Try putting a load on the tach i.e. headlights to see if it still jumps.

Why is my tach jumping on my MSD?

A bad pickup coil will cause erattic tach behavior but will also cause erratic missing, bogging, engine dieing while idling, and other various ignition related problems. An MSD uses the same pickup coil that your stock ignition system uses so the procedure is the same. Ludicrous speed, GO! I had a similar problem with the tach in my 73.

What should I do if my boat tachometer is not working?

Reconnect the boat battery to the boat wiring system. Turn on the boat and check if the tachometer receives a reading of revolutions per minute from the engine wiring. Give the boat some throttle and confirm the tachometer reads the increase correctly.

What to do if your boat’s tach jumps?

Try putting a load on the tach i.e. headlights to see if it still jumps. Hope someone elso jumps in here I am no expert, however, I installed an alternator on my boat and in the data sheet it mentioned that if the tach jumps, “just put a load on the circuit to correct”. LocationRoman Forest TX.

A bad pickup coil will cause erattic tach behavior but will also cause erratic missing, bogging, engine dieing while idling, and other various ignition related problems. An MSD uses the same pickup coil that your stock ignition system uses so the procedure is the same. Ludicrous speed, GO! I had a similar problem with the tach in my 73.

When it happens at idle, the motor lopes/lunges really bad. At higher rpm it doesn’t seem to effect running. It seems to do it more often on really hot days. Any ideas? Try putting a load on the tach i.e. headlights to see if it still jumps.

What to do if your Tach is jumping?

Take off your distributer cap and pull the rotor off, then locate the connecter beside your distributor where the wires connect to the distributor. Disconnect the wires at the connection, using an ohm meter check the resistance of the wires coming out of the distributor, right this number down.

Can a bad pickup coil cause a bad tach?

A bad pickup coil will cause erattic tach behavior but will also cause erratic missing, bogging, engine dieing while idling, and other various ignition related problems. An MSD uses the same pickup coil that your stock ignition system uses so the procedure is the same.