Exhaust valve question?

Ok folks a quick question on the exhaust valve just before the end can on a 2010 model.. the bike I bought had a fairly crude Home made decat (that managed to burn a hole in the belly pan at Almeria last month!) on it that retained the original exhaust valve. I?ve just bought a proper decat pipe for the bike and wonder firstly is the exhaust valve purely for noise and emissions or does it serve any other purpose and secondly anyone that?s put a full system or decat on the bike is it just a case of disconnecting and removing the servo cables?
Struggling to get access to the workshop manual at the moment..

Thanks in advance...

Growlee said:

I?ve just bought a proper decat pipe for the bike and wonder firstly is the exhaust valve purely for noise and emissions or does it serve any other purpose and secondly anyone that?s put a full system or decat on the bike is it just a case of disconnecting and removing the servo cables?

Click to expand...

The exup valves are essentially for noise emissions, though the added back pressure they provide at lower engine speeds does help to smooth things out a bit and is claimed to improve performance.

You can remove the exup valve cables, but must take care not to rotate the servo rotors or remove the servo motors as doing so will result in a warning light

Thanks Oli, just got the bike back today so not had a chance to test fit everything and see what?s what but will hopefully get to it tomorrow. A list of jobs to try and get sorted related to dodgy fuelling/ pcv map but wanted to start with proper decat as other option was trying to find a stock system to keep exup valve..

Just resurrecting this post briefly for some help hopefully.. managed to get some time this week to work on the bike. Fitted the new decat pipe but once all connected up I noticed I was still getting some exhaust gases blowing around the sump area. Initially thought it was the decat joint but now appears that it?s actually leaking from the pressed joint in the original down pipes just prior to the cat. The question I have is, do they all leak to some extent here? If you hold your hand next to sump plug with engine running can you feel the exhaust gasses blowing? It?s relatively minor but the gasses will get hot and the last thing I want to do is destroy another belly pan like the last one. When the last decat split apart on track the exhaust gasses burned a hole in the belly pan... starts getting expensive replacing those every few sessions!! The CRC fairings are nice but appear to be a very tight/ close fit around the cat area...

There shouldnt be any gasses coming out from where you describe. Have you had the opportunity to check for any cracks in the pipes?

Soofsayer.. yes had a look and it seems the pressed joints of the original exhaust are leaking. I can see daylight through the left hand pipe looking from the inside. I suspect I?m going to have to drop the whole system and most likely get the whole set up checked and seems welded. Will most likely get decat welded on at the same time I think as the clamps foul the belly pan. Just wondered if anyone else had had similar issues... not a bad time of year to work through these niggles!

Exhaust Gases

There should be absolutely no exhaust gas leakage. I would personally just do it properly and fit a full exhaust system as by the sounds of it you will probably save money in the long run.

+1 on the above

Thought as much... I?ll keep eyes out for a decent deal on full system but still sitting with old track bike at the moment so trying to get costs down. Thanks for the replies once again guys..