Coolant Leak on carb / heater outlet hose, Occasional high idle / deiseling

[gbeyschau]

Hey ya'll first post here. I've had my '86 D50 (118K miles, G54B) for about a year now, got it from an older guy who bought it new. He seems to have kept up on maintenance, though the only receipts I found are for the PCV valve, tires and oil. The only issue I've had was a valve cover gasket leak that I fixed, until now:

The other day after about 30 mins of driving around town I got home and was about to turn it off when it started idling at about 2,000+RPM and when I turned it off it was dieseling. Couple days later it started and idled fine. I've since been reading the heck out of this forum trying to figure out what's going on.

I took the air cleaner off and saw that there is some coolant leaking from one of the bolts on top of the carb, as well as the T where the heater outlet hose goes into the engine and T's to the Carb (see pictures, used a pencil to point the specific carb bolt). No coolant leak anywhere else as far as I can tell, though the engine is a little dirty from the valve gasket leak. The coolant inlet and outlet hoses on the carb have some crusty buildup too. No idea if this is related to the high idle / dieseling.

The water pump seem to work fine. There's no white smoke from the exhaust or coolant in the oil (as far as I can tell) and the coolant looks clear and smells like coolant hah. Also no coolant smell in or out of the cab. I'm wondering if there is some debris or buildup in the cooling system clogging something up somewhere? Something funky maybe in the electric choke? Hoping it's not the head gasket or a cracked head :fingerscrossed

This will be the 1st vehicle I've done any kind of more diagnostic work on (I've done a radiator replacement/brakes/valve cover gasket/belts on other cars). Can anyone point me in the right direction? Should I drain the coolant and start pulling hoses off? Check the thermostat? Try to clean out the electric choke? What's on the other side of that bolt on the carb?

I'd like to do a Weber swap eventually (mainly to get rid of the overly complicated Mikuni) but if the head is toast I'll save my money.


Thanks for reading and apologies if this is too long winded!!