Auto enrichener question, 2005 25 hp fourstroke, electric start, remote control

[halmc]

The ECM decides when the engine needs enrichening. However, my remote control, which hitherto has controlled an aging mercury four cylinder, two carb, two stroke, has a 'push the key' choke with attending wire back to the engine where it used to connect to the choke solenoid.

I'd like to use that particuar wire for another purpose but don't want to forego any manual control over the auto enrichener, if manual control is avaialbe.

I've studied the schematics in the shop manual and have come to the conclusion that the auto enrichener is aptly-named, in that it offers no manual control. Its control is the sole province of the ECM, that in its turn, references the ECT.

If I'm right, the wire that used to control the choke is available for other purposes.

Am I right?

(guesses are welcome, but remember that I already have one.)

 

[Capt Ken]

Re: Auto enrichener question, 2005 25 hp fourstroke, electric start, remote control

It does nothing. Just hangs out with the more important wires remembering the days it had a job. Actually the enrichment system works with a thermo switch not the ECM.

 

[halmc]

Re: Auto enrichener question, 2005 25 hp fourstroke, electric start, remote control

It does nothing. Just hangs out with the more important wires remembering the days it had a job.

Excellent! In that case it will soon be taking up another career! In fact, that wire has a great deal incommon with my own career path.

Actually the enrichment system works with a thermo switch not the ECM..

Hmmmmm.

According to the schematic of my 25 hp, the thermo sensor has two conductors, a black one to ground, and a tan w/grn stripe to the ecm via pin 11. The enrichener itself appears to my eye to be controlled by the ECM via pins 5 and 6. There is, on my engine, no direct connection between the ECM and the thermo switch. Hence it seems to me that the ECM takes account of the engine temperature through the ECT, and adjusts the "auto" enrichener accordingly.

That said, the obvious connection between the stator and the ECT is a bit difficult to explain. Unless it suggests differing settings to the ECM for the auto enrichener with differing rpm. (?)

On an other thought, is the auto enrichener a binary sort of device; i.e., is it either on or off, or can it vary over a given range?

 

[woody66912]

Re: Auto enrichener question, 2005 25 hp fourstroke, electric start, remote control

The enrichener is filled with bees wax, the stator supplies 12 volts the wax heats up and will slowly close off the fuel enrichment circuit.

 

[majordadsage]

Re: Auto enrichener question, 2005 25 hp fourstroke, electric start, remote control

I am having problems (have had them for quite a while) cold starting my 25HP Bigfoot 4 stroke Mercury. If I spray starting fluid/carb cleaner in the intake, it fires and after a couple of times, it will start idle and I won't have any problems with it the rest of the day. I have put a new enrichener on the carb, rebuilt/cleaned the carb, and I am making absolutely sure the gas I have is fresh. This engine will not start cold. It will start if I shoot some carb cleaner in the intake. Where is this "thermo switch"?