Tach question on 85 Johnson 150 GT... will auto tach work to troubleshoot?

[jskise3]

Now that I got my speedo and fuel gauges workin its time to tackle the tach. Now got to read the terminals yet to see if its 14 amps. However the other day I had to boost off my trolling battery cause started bat was near dead. A couple miles up the lake and got out of the water and the starter bat was reading 12.5 V. So im assuming my charging system is working. My question is can I check the tach by wirring up an old auto tach to see if its getting any type of signal? I know I cant use the tach all the time I just want to check to see if its the tach itself before ordering a new one? Any help is much appreciated thanks

 

[boobie]

Re: Tach question on 85 Johnson 150 GT... will auto tach work to troubleshoot?

First off, check the charging system on the mtr. Put a volt meter across the battery and run at wot. It should show 13.8-14.2 volts or so. If the charging system isn't working the tach won't either. I've never seen an automotive tach that would work on an outboard unless you have an inductive timing lite with a tach in it.

 

[laderwell]

Re: Tach question on 85 Johnson 150 GT... will auto tach work to troubleshoot?

First off, check the charging system on the mtr. Put a volt meter across the battery and run at wot. It should show 13.8-14.2 volts or so. If the charging system isn't working the tach won't either. I've never seen an automotive tach that would work on an outboard unless you have an inductive timing lite with a tach in it.

It sounds like you may have a bad regulator