Transalp XL650V - Catalystic Exhaust

[kandedaniels]

I am thinking of eliminating the catalyst from the exhaust on my Transalp XL650V. I have been told that if I do this no alterations eg: jetting etc need to be done. Has anyone removed theirs and if so have you notice any improvements in performan or mpg. I have heard that after doing this the bike will run slightly weaker but better overall. Please help if possible as I don't want to go ahead with it until I am sure it will not affect the bikes performance.

Here's hoping Someone can help
Ken

[Austin]

I am thinking of eliminating the catalyst from the exhaust on my Transalp XL650V. I have been told that if I do this no alterations eg: jetting etc need to be done. Has anyone removed theirs and if so have you notice any improvements in performan or mpg. I have heard that after doing this the bike will run slightly weaker but better overall. Please help if possible as I don't want to go ahead with it until I am sure it will not affect the bikes performance.

Here's hoping Someone can help
Ken

try searching Ken - here has been loads of posts on this including a couple recently along the lines of your question. In theory removing the exhaust allows the system to breathe better so it should run a little weaker, so in theory better MPG and as long as it doesn't go too lean, a bit more power.

For the record I have done it - ages ago. Its fine, saves a bit of weight and I probably said more power and better MPG at the time but too long down the road to tell now. TBH unless you enjoy the fiddling about and want to develop a deep and long lasting relationship with your bike, don't bother it doesn't make that much difference.

You need to take the exhaust off, cut off the "bulb" that is the catalyst and weld up the hole. Cut it really close to the exhaust pipes so it clears the swinging arm - then next time you take the swing arm off you don't need the exhaust off too. Once done cover your arse by getting it dyno'd too see how weak the mixture has gone and if you need any carb work to get the mixture right (I also have 125 main jets and a K&N and and a fairly loud/straight thru end can and the mixture is still fine) , in fact if you dyno it before and after you can tell how much more power you have and if you make a note of the fuel air/mix you should be able to demonstrate that you will get better MPG.

Good luck

[piguglyshandydrinker]

I think this is what Austin means.




From my own & others experiences - including dyno runs, removing the cat gives a little more power torque in the 3-5k rpm range (dyno shows a miniscule improvement...), although seat of the pants throttle response feels better, with a deeper engine note.

Fuel mixture, again is similar to previously (quite rich), so don't worry about running too lean.
Removing the cat alone will have little if any effect on fuel economy - this comes with correcting the fuel mixture - jetting/needles/filters etc.

As Austin says, do a bit of searching, theres lots of in depth info.

A dyno run is always advisable after any significant changes.



Phil

[rick001]

I had my cat removed, the muffler gutted a bit and did not have to have it rejetted.
It breaths a bit better, has a slightly nicer note and accelerates a bit faster, but it doesn't seem to have made much difference to the fuel economy.( maybe a little bit, but not much)

[kandedaniels]

Thanks for all of the info. I haven't yet decided whether to make the alteration or not - this is because we're always two up on the bike (me and my wife). Would it make a difference overall being two up instead of solo if I went ahead with the alteration? Any thoughts on the subject?

[The Pheasant]

I fitted header pipes from ABP Racing for about £200 including delivery, which do the same thing but avoid having to chop your standard pipes around. They flow a bit better and give a good (claimed) 10 % power hike with main jets reduced to 125. If you ride two-up a lot I'd say it is definitely worth doing for the extra poke.

[Frad]

I fitted header pipes from ABP Racing for about £200 including delivery, which do the same thing but avoid having to chop your standard pipes around. They flow a bit better and give a good (claimed) 10 % power hike with main jets reduced to 125. If you ride two-up a lot I'd say it is definitely worth doing for the extra poke.

Does it sound any different and have you got std can or a different one ?

[The Pheasant]

The silencer is the standard Honda one. Fit is possibly even better than Honda's own headers. 'Cos the catalyser also dampens some of the sound, the exhaust note is a little harder and punchier than with the cat-equipped pipes. Good, though, especially on hard acceleration but no way offensive or I wouldn't ride them.

[Frad]

The silencer is the standard Honda one. Fit is possibly even better than Honda's own headers. 'Cos the catalyser also dampens some of the sound, the exhaust note is a little harder and punchier than with the cat-equipped pipes. Good, though, especially on hard acceleration but no way offensive or I wouldn't ride them.

Thanks I agree I wouldnt want anything too loud but this looks interesting, one other question......... what about emissions and MOT? does it still pass?

Cheers

[The Pheasant]

As far as I can ascertain, there are no issues cos the header pipes are not subject to any controls. Ie, there is no test they have to pass. Only the silencer has to pass any standards and have the relevant markings, which of course the standard one has. Although pre-'08 motorcycles such as the 650 Alp were made to comply with Euro2 emissions regs, there is no MoT emissions test for pre-'08 bikes to ensure they still comply with Euro2, so the cat can be discarded. '08 and later bikes will apparently have to pass an emissions test for Euro3 at MoT.
Anyone know otherwise?