Bike shuts off mid-motorway - Tach also goes crazy!

[p.dath]

+1 to electrical issue. Check battery, regulator/rectifier and stator .

[FJRider]

Either that or your powerband is as lose as your chain , which may explain the elastic thing

The wrong colour Powerband might cause those issues ...

Shit in the fuel might too ...

Swap the Hyo for a few packets of M & M's ... and get a Yamaha. (problem sorted)

[ducatilover]

As said start at the battery and then go to the starter relay and clean all the connections there
Hyobags tend to shit ignition switch contacts too. I've dumped a Suzuki ignition switch in the one I picked up.

Backfiring is the bike running lean, check the exhaust has no leaks, but if you have a wank exhaust on it, it'll need jetting, common jetting is to go up one size for just the muffler, so swap the jet from the rear cylinder (97.5 I think) in to the front and buy one #100 for the rear. Make sure you get Mikuni jets, Dynopro, Factory pro, Keihin etc all use different numbering even though the jets fit the same hole.