Also, just for the record ... took the cat code plug (dark yellow) off my 52-plate BCR (Y-piece, K&N, standard cans) to see what happened.
I would like to report back that it "feels" a lot stronger and smoother (also reduces the feeling of extreme snatch when I come off the gas at low speeds) ... but unfortunately it also leads to the most herrendous occasional backfires. So I have put it back in.
I assume the backfiring is due to an over-rich mixture? Although the Y-piece and K&N would mean leaner running.
All good fun, H27.
PS: Apologies for mention of "extreme snatch" ... but I think we might get a few more hits once the search engines pick it up
2007 Suzuki Bandit 1250 Street Fighter
2001 Triumph Bonneville
1976 BMW Ex-Police R75/6
1953 Ariel NH350
Steptoe's box looks different because it is horse27. The pictures taken from his GS. Not sure which plugs are linked tho, check out the ukgser site for more info, he's a bit of a guru.
On another note Steptoe if you pop back to read this, do you still do stainless bolt kits?