Hi guys, i need some help, my DL50 was running ok in test stand, but in the airplane ( Yak 54 GP) start with the choke and stop inmediately, spark is ok wires ok fuel ok but start, run 5 seconds and stop. Any ideas??? thanks! [:@]

Do you mean it only starts with the choke on or?

Do you have a servo on your choke?

Fuel supply. Or throttle linkage isn't opening far enough. Only two things it can be, if it does the choke run.

If it stops in 5 seconds it's not heat related.

I would tend to think that you have the linkage to the carb backwards or something silly like that. Get a dental mirror and look through the open choke to see where the throttle plate is with it at idle and at full power. When you look in the carb you should see the threads of the throttle plate's screw, not the head of it.