I'm riding an '05 VTR, recently fitted with Staintune slip-ons and K&N high-flow air filter. Definately made a big difference to power, especially with the baffles removed from the cans.

Problem is bike can't seem to hold a tune... I've had it since new, and every service it's had it runs really well, nice smooth power, starts easily for a couple of weeks and then just starts to get rough. After fitting the pipes/filter had it serviced/tuned, and ran beautifully for about a couple of weeks before back to old tricks but more pronounced this time.

Usually starts first time with choke on, now requires complicated choreography of clutch, throttle and start button and backfires at least twice before starting.

Main problem though is running rough at low/mid revs (3-4k) and with throttle steady. It lurches along, with revs moving +- 500 without touching the throttle. At idle it's fine, although will often stop dead with no warning. It's done this a couple of times whilst cruising along too. Under acceleration it's better, although down on power and seems to be really straining rather than opening up like it used to.

Otherwise I really rate the VTR - I ride it every day and any weekend I get the opportunity, with a couple of good long runs every few months (Phillip Island in March and September!). About to do my first track day in 6 weeks time, and love to have this solved by then.

I'm thinking about a carb kit to improve fueling to match the filter/pipes. Is this likely to solve the problem? I've read plenty about Dynojet products - are these the best to try, or are there others?

Thanks in advance.