Runs but rough. Starts low power. Where to start. Also what is this?;

Just learning my way around.

 

I think what you have circled is the "Otter Switch". It is a Bi metal thermal switch which controls the automatic enrichment device (choke also called the AED). When the engine is cold the "Otter switch" allows the power going to the AED to have an earth and the solenoid on the AED engages switching it on. As the engine gets warm the Bi Metal strip in the "Otter Switch" opens and cuts off the connection to earth, the solenoid on the AED shuts off and the AED (choke) switches off. There should be a wire going to the AED which is live and a second wire going from the AED to the "Otter switch" to create the earth when it works. The "Otter switch is set to around 35 degrees centigrade I am led to believe.
There has been a lot written and spoken about the "Otter switch" as in older life it can fail either staying open or stays closed meaning you have a constant choke or no choke at all. Many on this forum including myself have changed to a manual switch on the dash which allows us to switch the choke on or off when we want.

 

The thing you have circled is a thermal switch or Otter switch that turns on the mixture enrichment device or AED on the carbs for cold starting ~ cuts out at about 35 deg coolant temperature.. Many have modified to a dash switch so they can manually activate the AED (Takes the place of a choke).

For the rest ensure that she is in an optimum state of tune. AED working, good plugs correctly gapped, healthy leads, points, condenser, distributor cap, coil, rotor, correct timing, healthy battery and proper earthing of the body to the engine.


AED






AED thermal switch.(Otter Switch)

 

Snap.

 

Got to get up earlier Glyn. lol. At least our answers did not contradict each other.

 

My post shows the same time as yours on screen LOL. Imagine if our answers had been different. That would have been a right royal mess.

 

You guys are BOTH quick and awesome. High fives all around. So does that mean that the switch under the steering column indicates that the otter has been bypassed?

 

It starts and runs roughly. Low power. In what order should I proceed.

 

Possibly. There are two ways to by pass the "Otter switch. The AED is always live and the "Otter switch controls the earth.
The easiest is to install a switch between the AED and earth so the "Otter switch" is no longer needed.
The second way is to have a switch on the power side so you can control when the "otter switch is on or off.
I actually have a switch ( a second rear window demister push pull switch with the warning light) to control the live to the AED and a permanent earth on the otter switch but this is only for the winter as the temperature on my "Otter switch is too low and it turns off far too quickly for winter running. In the summer I disconnect the permanent earth allowing the Otter switch to do its job but with the rise in ambient temperature the engine runs fine quicker with no choke.

 

How well does it run once the engine is fully warmed up ?
This is a carbureted engine with a choke, it won't run that great until it's fully warmed up, it requires patients until it does.
It won't charge out of the gate like a modern fuel injected car when the engine is cold and just started.
If you set the choke so it does, it will run way too rich.

This all assumes that the timing and over-all mixture is set correctly when it's fully warmed up with good plugs, wires, points and condenser.

Does it only run with low power when the engine is cold ?

 

Generally, if the otter switch isn't operating the starting carbs, a cold engine will be difficult to start and run rough if it runs at all. If it stays on, the engine will stall once warmed up. The precise sensitivity will depend on the ambient temperature.

 

I'm going to leave it to Cass. There is no point in us repeating one another.
I'll keep an eye out where I might have something useful to add.

 

Thanks Glyn. lol.

Do you know that the AED is actually working with your switch? Turn your ignition on and your switch then disconnect and reconnect one of the wires on the top of the AED. Does not matter which one. If the AED is working you should hear the solenoid jumping up and down as you tap the wire to the terminal.
If the AED is working but the engine is running rough when it initially starts then the AED needs tuning and this can vary depending on the ambient temperature. A summer setting will not start and run the car smoothly in the winter and vice versa.
If you look in the service manual you will see how to tune the needle on the AED to get the engine to start and run smoothly.
If the AED is not working then check your wiring from that switch to give you power to the AED and an earth.
Make sure all the other bits are running well first before you start fiddling with the AED ie timing, carb tuning, plug gaps, distributor points gap, good fresh fuel. Its a bit of a chicken and egg scenario in that the engine needs to run hot to check the timing, plugs and carb tuning but needs to run cold to check the AED but you need to get the engine running smoothly before you can adjust the starting on the AED.

Glyn will now post a diagram of the starting car needle and pages from the manual showing how to adjust it. Thanks Glyn over to you.

 

I regret the size variation. To shrink or blow up push Control - or Control +

Excuse me being economical with forum space.

 

You are a star Glyn and thank you. I don't have access to the pages on a computer like you with the ability to post them unless I scan them all in. Long and laborious so thank you again.

 

Windows 10 has a Snip feature. If you can see it on screen you can take a snip of it and send it. Much easier than scanning.

 

Most (or all) versions of Windows have what's now a fairly ancient program called Paint. You can copy just about anything into it and crop the picture, remove everything outside a selected rectangle. It also has a reduce size function that reduces the resolution of a picture. It makes the size of files more manageable and you can reduce a lot without consequences for display on a computer screen. Of couse, none of this is much help if you are starting from hard copy ...

 

That "Snip" feature has been around since XP, probably since the beginning as computing power allowed it.
"Copy/Paste" is another good one for word documents, I think everyone knows about that one.

 

Some versions left it out just to confuse the issue. I use it all the time & it sits in my tray. Microsoft is a pain. Premium versions. Plain Vanilla versions etc.

 

BTW ~ re reading this I can assure you that Otter Switch is not connected. Green & Black wire.