Just got a 78 XS750SE for FREE from a friend at work, as well as an extra for parts because her son got tired of it. Apparently the son dicked around with the Carbs and couldn´t get it to run anymore. After five hours and some minor adjustments got the thing to turnover, run rough for a 1/2 minute and die, couldn´t pursue the matter because it was late, there are no pipes, and the kiddies were sleeping. Thanks for the info on the gas tank and the PRI/ON/RES issue, I´ll be sure to get the petcock turned to the ON when I get home. Hopefully I´ll get this bad boy tuned up and on the road for this summer and tons of riding!