Ever since I bought it, it has had some starting problems - it would start OK on full choke, but would die if given some throttle. I had to let it tick over (idle) for about 5 minutes until I could push the choke in, then it would run normally. This was OK until the weather turned colder when it wouldn't start at all. I eventually got it started by heating the carbs with a heat gun (gently!), and it would usually start, though sometimes only on the left cylinder until it was fully warm when the right cylinder would start.
As I wasn't using the bike over the winter I left it, but recently as I'd booked a two week holiday on it in May, I thought I'd have a look at it. I've been very busy at work recently, usually working weekends, so I decided to book the bike into the local Triumph dealer for a service and to sort out the starting problem, which I assumed was blockages in the starting circuits of the carbs (the bike had been sitting for a while before I bought it). Unfortunately, the dealer is in the process of moving premises, so couldn't take the bike in for a month, so I decided to do some of the other jobs that were needed.
First of all was a new battery. The existing one was a dubious brand I hadn't heard of, and probably made in China, so wasn't helping with the starting as it ran down quickly. I replaced it with a Motobatt.
Next were the brakes. I'd read in reviews that the Bonneville's brakes aren't the best and those on mine were terrible. Front needed a very hard pull and the rear barely worked at all. I ordered 2 rebuild kits (they are the same, front and rear) from here on Ebay.