181 rough running warm

[laurent4224]

Hey folks we have a 181. Just getting it back on the road for the first time in 10 to 15 years
Its starts up just fine from cold (although will start easier if you dont tap the throttle to reset the choke as you normally would..??)
Anyways it'll start and run nice from cold. Do about a kilometer or 2 and will then become a bit rough at low rpms, as if its running out of fuel. And then has difficulty holding idle.
If although if i then floor it, it'll accelerate nicely, smooth and strong, up a hill so under load its fine.
If i let it sit for 10mins then it'll drive ok for a bit.
Things I've done then:
-Carb removed clean out all jets. Freed the ball bearing blocking off flow to the accelerator pump. Believe theres another but not touched it..
-changed oil
-fuel lines+ filter
-valve adjustments
-points cleaned checked adjusted
-plugs
-checked rotor and cap, looked good didn't change them
-looked for any vacuum leaks spraying cleaner whilst running, no change in rpm.

Now we were wondering is it overheating? Could this be a symptom? I can hold the dipstick with my hand but maybe i just have résistant hands.. Thermostat is opening fully. Just does still seem hot.
Otherwise what should we be looking at?

Any help greatly appreciated

[Wildthings]

If it will start easily without the choke then the needle valve may be leaking through or the idle jetting is too rich. How hot is your intake manifold getting? It sounds like it might be icy cold. Do you have an aftermarket exhaust without the ports for the heat riser being drilled?

[laurent4224]

I will have to check the manifold and get back to you on that, but i think its gets hot. The whole engine bay seems pretty hot to be honest. The exhausts are new on both sides original pieces with heat risers.
Needle valve, this the valve that regulates fuel into the float bowl? I did test this while cleaning out the carb seemed to work just fine. Also idle jet will be the stock one
To me it feels like theres not enough fuel when its hot and like you maybe to much when cold

[laurent4224]

Looking at the spark plug id say its running lean. Definitely not rich.
Intake manifold gets hot. All gets very hot. Guess when it over heats it leans out?

[laurent4224]

Figured it out this evening. Swapped in a new empi carb that we had on one of the beetles, slight adjustment, thing runs mint now! Must have missed a passage way on the old carb when cleaning it. I'll have a mate clean that with his fancy machine thing before using that one again