My 85 brat dies if i let off the gas in the first 30 seconds after startup. After that the engine is warm and it purrs at 7-800 rpms. However in that first 10-30 seconds if i let off the gas the rpms drop to 4-500 and it usually stalls out. Also, about 1 in 10 times when i turn it off, it diesels for a second. Any suggestions?

The choke isn't working entirely as designed. There are two parts to the choke - the choke plate iteself, and the mechanism that increases the cold idle through a three-notched cam. It's basically not serviceable easily on the car. If you dismount the carb you might be able to correct it on the bench but it also might just be worn out. If it's otherwise running OK and you just have to baby it for less than a minute in the mornings..... leave it be. The Hitachi's are complex machines and if it's working good beyond the first 30 secconds.... you are miles ahead of where you could be and you might cause more problems than you solve messing with it.

 

GD