I have one and I think it's 1978, it runs well and has been very reliable. The only problem I had was recently when the carby went rich. I couldn't find the problem but after I took off the float bowl and flushed the needle and seat, and reassembled it, all was fine. Must have been a bit of crap on the needle and seat. The major disadvantage of this system compared to the plastic carby is that all the cowling needs to be removed to remove the carby and then remove the float bowl. With the plastic carby only the brass screw/jet needs undoing the gain access to the float, needle and seat. Interestingly, I was able to complete the mowing job (about 20 min) with the carby playing up by judicious use of the throttle and the fuel tank tap, but the mower would not idle when I emptied the grass catcher.
