Whitehouse K17 mods...

[Bazbro_imp]

Are you adding fuel in any method? Removing the cats will lean out the mixture...and these bikes run lean enough as is.

I'm not removing the catalysers, PD.
The Wyvern paperwork shows a picture of a catalyser along with the exhaust pics, which I'm assuming is fitted, because the paperwork also includes a Certificate (of Conformity?). It's all in Japanese at the moment, but I'll translate it tomorrow.

It's just the O2 Sensors that I'm not fitting, as per the Forum discussion link. I know it might be controversial, but I've read the evidence and, as it's VERY common to remove these Sensors (on a great many different 'bikes. with corresponding smoother running) I think it worth doing.
(And I've just noticed that I mis-wrote "dissembling" instead of "disassembling" in my write-up - a very important difference! I can't edit it out now...) Red Face

I'm not removing the catalysers, PD.
The Wyvern paperwork shows a picture of a catalyser along with the exhaust pics, which I'm assuming is fitted, because the paperwork also includes a Certificate (of Conformity?). It's all in Japanese at the moment, but I'll translate it tomorrow.

It's just the O2 Sensors that I'm not fitting, as per the Forum discussion link. I know it might be controversial, but I've read the evidence and, as it's VERY common to remove these Sensors (on a great many different 'bikes. with corresponding smoother running) I think it worth doing.

Here is the relevant part of the Instruction sheets, PD. It's the reverse of the exhaust gas test sheets...



The top drawing (of the whole system) shows the position of the catalyser, in red.
The red writing says that you can visually check on the presence of the catalysers by shining a penlight into the forward end of the silencer. I imagine that this could be important in some markets, to prove "Conformity".

The photograph to the left of the red writing shows an actual catalyser, as fitted to these silencers. It describes the catalyser as follows :-
Outer diameter 56.3mm
Length 80mm
Number of 'cells' 300

All this information is on the back of the "Japan Vehicle Inspection Certificate - Vehicle Exhaust Gas Test Result Certificate". It's all in Japanese, but should be sufficient to satisfy the Authorities in whatever regime you find yourself.