Electric choke hook up
 

I have decided to hook up the electric choke on my carbs and not sure where to get the 12v from. I wired them up to the POS on the coil because it was neat and convenient. Looked at the carb directions to see how to properly adjust the choke and in bold lettering is says DO NOT ATTACH TO THE POS SIDE OF THE COIL. I looked around on this site for an answer and saw on another post that it should be hooked up to the oil pressure sending unit? Is that the correct connection point? Thanks for your help.

It shouldn’t hurt anything wiring to the coil but it most likely won’t open all the way with less voltage after cranking. I wouldn’t wire to oil pressure sender as I’d think that could alter readings. Just a guess but try and go directly to a 12 volt ign activated by key. JMO

That was my thought however, "electrically speaking" that is the same location that I wired my coil to. I'm talking about the remote relay. I think that's the home base for "keyed 12 volts" isn't it? My other idea was to wire it to the block that is powered with the main battery switch. Thanks for your help.

Dont wire it to the coil

when they say oil pressure switch they do not mean the one for the gauge. in the 80's most carb motors had a second switch teed off the op switch that had two posts. when is saw oil press it would close the switch and power the choke. this kept the choke from heating up if you were KOEO. they look like this Attachment 577664

What engine do you have?

This is what is shown for a HP 500 carb engine. It has a SWITCH choke (#16) that mounts to the oil filter head.

https://www.marineengine.com/parts/m...er-and-adaptor

Unless you are boating in really cold weather, you don't need a choke. Never had one hooked up on any of my carb engines and never needed one.
Pump throttle a couple times, start engine, throttle up to 1000-1200 rpms for 30 seconds and done.

2 quick pumps and a shoulder roll takes care of business. :)

Stay away from the coil +. Yes, i’ve been dismissed on this, but whatever.

Connecting to coil + will pull down the voltage available to coil. Probably wouldn't notice it at idle but at higher RPM the coil draws more juice. Could lead to weak spark at higher RPMs.

Never had a working choke on any of my boats either. On my current boat I have it held fully open with safety wire on the linkage.

Some setups use ballast resistors on the coil+ supply line. Coil gets 12v while cranking (from the start terminal on the key switch) and then in the run position the coil sees about 9 volts or so. If your coil receives full 12v ALL THE TIME while running, then that is an acceptable power source to power the choke.

But it is not the best choice. Will it work? Yes. Will it hurt anything? No.

An oil pressure activated switch is a good idea for the choke power for reasons mentioned above. But in reality, there is no good reason for your ignition switch to be in the RUN position when the engine is not running, so the benefit to using a pressure switch sort of vanishes for that reason.

The choke needs to see 12v+ when the key is in the run position. The - side of the choke can be grounded at the manifold (or grounded thru an oil pressure switch).

Cold choke winding = full choke.
Hot choke winding = open choke.
Winding heats when power is supplied.

Don't overthink it.

You really don't need the choke - I'd yank the assembly off the carbs and pull the choke plate and shaft - it's not needed. Mine will start, in 30 degree weather without a choke (emergency winterizing). They may complain a little at that temperature, but after about half a minute or so, they're good to go.

Also, as mentioned above, the reason not to use 12V from the coil is due to the use of ballast resistors - ballast resistors were used to drop voltage at the distributor in order to make points live. I don't think any of us here are using distributors with points so it's really no longer much of a consideration - Holley leaves it in the instructions to cover their arses.

Dump the choke.

On Holley's go one better and mill the choke tower off too. Instant Dominators! :lolhit:

Woohoo!!

:boat:

Thanks everyone for all the help. I will not be hooking up the chokes after all.

I agree with no choke, also never enabled mine, however if you decide to proper voltage location is voltage sensor terminal on alternator.

Typically best Holley idle mixture screw setting is about 1/4 turn out (rich) from best warmed up idle in neutral .

Less finicky ‘cold starts’ and good putting in gear drivability when warm.

As always, Your results may vary.

Note: engines with even mild camshafts will enjoy more initial timing. Even a few degrees can make a world of difference.

I switched to higher output single wire alternators a few years ago. Is there a location on this type of alternator for the choke connection? I have no idea what the initial timing is on my new engines but I know the total advance is 33 degrees. They start fine just cold blooded. Neither will idle cold below about 1700 rpm's.

IDK I am not at home so cannot look at my spare.

It'll be fine - I wouldn't even dick with the whole choke thing.

That's a tuning issue. I'd find out what your timing is at idle and tune the carbs. (unless you're talking 45°F and below)

What rpm do they idle at when warmed up to temp??

It's very possible that they need a final tune. The only run time they have is on the dyno. The other day was the first time on a hose and with the wet exhaust and the idle once they warmed up was 900.