My 1976 Spitfire 1500 CC has an issue where it dies after around 5 miles. During the time that it is actually running it backfires multiple times. I can get it going again but it dies again after a mile or so. This has only happened twice so far in the last 6 months and on both occasions the weather was fair. I use it regularly for 3-4 mile trips with no issue. For the record the battery is less than 6 months old.
Has anyone had a similar issue or can offer some advice as to what may be causing my problem?