Sensor Checks 1971 Johnson 50 HP Electric Choke/Shift

[Somerowl]

Happy Friday y'all,
I'm in the middle of rebuilding my old 50 Johnson and wanted to know about the sensor on the Cylinder Head and the one on the Exhaust side plate.
1) Are there any ways to check their function?
2) Do they need to be functional or can their function be replicated with aftermarket products?

Thanks very much for your assistance, I did a search, but came up empty.

:help:

Nick

 

[F_R]

No Title

There is no practical way of checking the overheat sensor in the head, other than run it hot--and I wouldn't call that practical. However, you can bare and ground the wire (with key turned on) and the overheat horn should blow.

As for the choke sensor, there was a factory service bulletin advising a modification that does not use the sensor. With the mod, the choke operates in full choke mode when you hold the choke switch--and only when you hold it.

 

[Somerowl]

Great, thank you very much. I like the MOD for the choke circuit, but it looks like you can remove the thermal switch altogether, is that the case?

 

[F_R]

Sure you can, but why? It wont be doing anything after the mod, but it won't hurt anything by being there either. Save the effort for something else.

 

[Somerowl]

Good point!