Got an 82 GL500 Interstate that I've had for about five years now. Been running into a peculiar problem for awhile. With the engine cold, choke on all the way, press start, the engine starts and then revs upward to around 3K rpm until I push the choke inward and the revs drop down. Then engine begins to bog and die and I pull the choke back out again. The engine revs back up to 3K rpm or so. This goes on until the engine warms enough such that I don't have to play with the choke anymore. I have rebuilt the carbs and made sure all the jets and ports were clear including the low speed jets (removed and cleaned them). Still the problem persist. I am going to check the timing and valve adjustments along with the throttle and choke cables again and post the results. In the meantime, if anyone has had a similar situation, let me know what you found and did to eliminate the problem.