I filed this under a previous thread and think it should be under a new thread. reproduced here.
Thanks for that. Will pull it and see. Looks OK and turns easily. I re-oiled it but suspect the problem is the tach itself since it works fine for maybe 10 minutes and then hangs up moving just slightly near 1000rpm with a change in rpm.
A couple of other questions. The car was changed to negative ground and the choke (starting carb) connection to the sensor disconnected. I'm guessing the solenoid would not function properly with the voltage reversed and so the reason for disconnecting. I was hoping the solenoid was isolated from chassis grnd but measures a few ohms from one side and 16 ohms from the other. Others have done the positive ground conversion. I wonder if there is there any other solution so that I can get some choke function on startup?
__________________

Glen
1959 XK150S, OTS 3.4L
2014 BMW 535XD

 

Most of these chokes were disconnected because the PO was not going to pay for a new temp sensor or the time to fix the choke solenoid. It is not required to reverse wire the solenoid. Take a test and see if solenoid is still viable and take sensor and heat in a glass of water to see if it is in specs with the manual. Lots of solenoids were disconnected also, because they ran too long and fuel prices back then, even though lower than now, were an issue along with sooted plugs. Back then you usually checked plugs weekly.

 

The temp switches (OTTER SWITCH??) were unreliable.

Coils of wire to make an electromagnet really don't care what direction the current is flowing.

Put a switch under the dash like everyone else and remember to shut it OFF when the engine warms a bit.

bob gauff

 

Thanks to both on the starting carb. I did read that others have simply wired a switch and if the relay still works will try it. The temp switch has lost its spade connector on top so the switch sounds like the best way to go. Must try a manual application of power to the solenoid and see if it is working.

 

mine went south on my '52 xk120 back in the seventies, and being just a college kid in rural Vermont, and there being no internet at the time, I stuck a penny in the hole, which fit pretty well. it did pop out and kill the engine sometimes under severe engine breaking, but I used epoxy to keep the last one in. If you are the guy from Ct. who bought it from me in '78 0r so to restore it, sorry about the epoxy and all the other clever and not so clever fixes. anyhow, I never had any trouble with starting mixture without the aux starting carb working, just sayin', in Vermont.