Motoduc84

Greetings: Just learned of this site...and I will be here a lot! Longtime Yamaha rider! Anyhow, last year, my older brother passed away...and his family is asking me to sell his 1976 DT 400. It is very clean and was ridden only 3,800 miles over the years. Which is probably the problem here. It starts easily with the choke on and will run fine like that, but when you take the choke off...it dies. There was a lot of varnish in the carb, but I have sprayed and used air pressure and I think the jets and various holes are clean. But the problem persists. I have considered a new carburetor and it seems like there are plenty of Mikuni dealers around. But I am concerned about the right fit. Will a new Mikuni have the right plug for the auto injector? Other issues, perhaps? There does not appear to be any leaks around the carb manifold and it runs too strongly to have a bad crankcase seal. Any help would be greatly appreciated. Thanks. Kent