I purchased a used 06 Repsol 4RT to see how I got on with a 4 stroke and am now a complete convert.

 

Going through the various spares and bits in bags that came with the bike recently, I found 2 used sleeves with flanges that appear to have been previously fitted somewhere in the exhast system; according to the wonderfully concise manual, one of the sleeves looks like it fits inside the header pipe where it bolts onto the cylinder head and the other sleeve looks like it fits in the silencer socket which slips over the other end of the header pipe.

 

Are these items removed for any reason?

 

I do know that the diffuser on the back end of the silencer does make a difference to the noise if removed but probably does not affect performance but what about these other 2 items?

I purchased a used 06 Repsol 4RT to see how I got on with a 4 stroke and am now a complete convert.

 

Going through the various spares and bits in bags that came with the bike recently, I found 2 used sleeves with flanges that appear to have been previously fitted somewhere in the exhast system; according to the wonderfully concise manual, one of the sleeves looks like it fits inside the header pipe where it bolts onto the cylinder head and the other sleeve looks like it fits in the silencer socket which slips over the other end of the header pipe.

 

Are these items removed for any reason?

 

I do know that the diffuser on the back end of the silencer does make a difference to the noise if removed but probably does not affect performance but what about these other 2 items?

My 05 came with three restrictors in the exhaust system as you describe, the separate instruction leaflet accompanying the bike noted that they were for compliance reasons and should be removed for full power in competition set up. My dealer advised leaving the smaller diffuser at the end of the silencer to give max low speed torque.

Over here the 06 Repsol came without any of the compliance parts such as lights and restrictors etc.

File them in the scrap bin.

As indicated, they are for certain types of registrations in some countries and not needed if using for competition only.