mid winter checking in

[the old grind]

Here's a scan of the electrical page from the manual. I see the "M" on the switch

View attachment 457291

GTS, then, like the earlier Hondas. (GX-630, 660, & 690 are GTR if you upgrade)

What I did (because the generic relay with socket was 'hanging around') was to tie the Low Oil Shutdown and coil wires to the NC term and ground the 'commons'.

When the relay is energized they are 'open'. Either LOS or de-energizing the solenoid grounds the coils and shuts 'er down. Be sure to tie the two together after the relay and not between relay & ign terminal so LOS will function normally.

If I had to pay for the relay I would have replaced the switch instead, pro'ly cheaper but surely simpler. Easier to find this type switch on the rack than on their website, but Advance Auto is where I see switches with 'M'. tog

 

[Alan7s]

OK thanks, I'll take a look there. One more question which shows my lack of knowledge in these things. Why doesn't just cutting the power
to the coil stop the engine? Why would anything need to be grounded to stop?

 

[the old grind]

It's just one of a few ways to control the ignition on the primary side. Not all applications have 12v systems other than for starting. (T5c only has lighting) Since this is really a magneto setup, only needs the secondary (it's grounded internally) circuit path to do the biz. If the throttle stuck WFO, would you like to pull plug wires if spurting fuel or your upside down? ... :laughing:

Ground to run is safety drive. A broken connection to dead-man or 'M' terminal with a magneto-fired engine leaves stalling, fuel starvation, or LOS as remaining shutdown possibilities. Needing a complete connection to keep 'er running means if stuff falls apart it can't 'run on' should SHTF.

Be aware that whether your T-M is GTS or GTR do NOT wire 12v to the coils from the ign switch or anywhere else. They will fry in short time. (They are all self-energizing.)

I can put up switch ladder diagrams and maybe links to sources of both switch types tomorrow. (SC, or wherever) These could help one vet a switch with confusingly-marked terminals if they go shopping around.