Mercruiser 3.0 TKS question

[fairshopperguy27]

Does anyone know if I could ditch my TKS CARB and just go back to a standard electric choke mercarb while still using the TKS wiring harness? I've had nothing but problems with this TKS carb and am thinking about just purchasing a reman mercarb with electric choke. The TKS plug in the harness that goes to the carb has two wires: one black and one red/purple wire. Can I simply cut the plug off and put on connectors and run them to an old style carbs choke? It's just gotta be more complicated then that. But?

 

[alldodge]

What is the year/serial number

 

[fairshopperguy27]

What is the year/serial number

It's a 2005 3.0LX serial: 0W302229

 

[alldodge]

Going to mention Fun Times and muc incase I'm missing something.

In looking at the wiring diagrams of the motor and manual 41 (TKS) it appears to me that there is only a power and ground going to the carb for the module. If this is disconnected and not used I don't see a problem with running a regular carb.

 

[fairshopperguy27]

Going to mention Fun Times and muc incase I'm missing something.

In looking at the wiring diagrams of the motor and manual 41 (TKS) it appears to me that there is only a power and ground going to the carb for the module. If this is disconnected and not used I don't see a problem with running a regular carb.

Thanks, I would be using those two wires to power the electric choke on the old style carb.

 

[muc]

I've worked on very few of these, but if I remember right the ground for the TKS goes to a temp switch so you shouldn't use that. I remember something about a diode on the positive side but I don't think it would matter for an elec choke.

 

[Fun Times]

On the 3.0's the red / purple wire has continuous 12 volt power supply. The oil PSI switch sends/provides a ground path once oil psi builds up activating/completing the TKS mounted module via the Black/Yellow wire. If you connected the red/purple wire to a normal choke, it would be on all the time even with the engine turned off unless you disconnected the battery.

You'd have to tap into the/a purple wire that will turn on and off with the ignition key + add a whole new ground wire not using the Black/Yellow wire as that wire is tied into the oil psi switch which basically turns on and off too with oil psi.

I do believe the bottom gasket between the two designed carbs are different too.
TKS gasket number 32, http://www.mercruiserparts.com/bam/s...30905/4893/115
Mercarb, number 26, http://www.mercruiserparts.com/bam/s...30905/4893/100

For references, You can find the two designed carbs and related parts all within this one parts link, http://www.mercruiserparts.com/3-0l-...0-thru-0w30199

 

[fairshopperguy27]

On the 3.0's the red / purple wire has continuous 12 volt power supply. The oil PSI switch sends/provides a ground path once oil psi builds up activating/completing the TKS mounted module via the Black/Yellow wire. If you connected the red/purple wire to a normal choke, it would be on all the time even with the engine turned off unless you disconnected the battery.

You'd have to tap into the/a purple wire that will turn on and off with the ignition key + add a whole new ground wire not using the Black/Yellow wire as that wire is tied into the oil psi switch which basically turns on and off too with oil psi.

I do believe the bottom gasket between the two designed carbs are different too.
TKS gasket number 32, http://www.mercruiserparts.com/bam/s...30905/4893/115
Mercarb, number 26, http://www.mercruiserparts.com/bam/s...30905/4893/100

For references, You can find the two designed carbs and related parts all within this one parts link, http://www.mercruiserparts.com/3-0l-...0-thru-0w30199

Thanks. Would the purple wire that plugs into the shift interupt work?

 

[Fun Times]

While harder to do on your design coil, getting power closer to the coil would be considered a better idea, it will work okay coming off of the shift interrupter switch purple wire too.

Also in order to excite the 12v power circuit to get more voltage quicker coming out of the alternator, be sure the engine get's revved up to a Max RPM of 1300 when first started cold before just letting it idle at a low RPM while cold for a long period of time during warm up at the dock.