Fitting decat Y piece/ cat removal

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sjrainsford
Posts: 70
Joined: Sun Sep 24, 2017 11:44 am
Location: Lichfield

Fitting decat Y piece/ cat removal

Postby sjrainsford » Sat Apr 28, 2018 2:59 pm

Afternoon all!
Given the rubbish weather a decided to do a bit of spannering in the garage. Only problem is I’ve not really got room.
Anyway with a bit of stretching over/ under the bike I’ve got all of the fittings undone ready to remove the cat.
As I can’t really get to the back of the bike I’ve decided to leave it until I can wheel it out in the dry.
How do I actually get the cat out and slide it off the back box pipe? I presume I need to remove the back box. Couldn’t really see how though.
Any tips to remove the cat?
Thanks in advance!
2001 BMW R1100S (Merecat)
2008 Vespa GTS300 (Bianca)

Neil178
Posts: 648
Joined: Sun Aug 29, 2004 11:24 pm
Location: East Mids

Re: Fitting decat Y piece/ cat removal

Postby Neil178 » Sat Apr 28, 2018 6:46 pm

Oh gawd, it’s been too many years to remember properly so your best course of action is not to bother reading anymore of my post! However, if you like adventure ...
There are some fixings underneath the rear exhausts to undo. With the spanners handy undo the cat to rear exhaust clamp.
Then it’s a health spray of WD40 or similar and a firkin big hammer and a block of wood to prevent damaging the back boxes by spreading the force. Also a trap for your thumb or fingers to get caught in.
Now get some Beer in the fridge to cool ready for your success.
Twat the back of the boxes using mucho swearing and blasphemy untill they separate.
Mine were a total bas•••d and I needed that cold beer after. I hope yours seperate easier.
Did you manage to undo the Allen bolts on the cat? I had to dremal mine off.
I might have removed the rear wheel(rear shock too?) for access, as I remember the bike wasn’t properly supported and I ended up with one of those ‘oh feck’ moments.
Have fun!

England
kfrogzx7
Posts: 235
Joined: Tue Jul 15, 2014 9:25 pm
Location: Suffolk

Re: Fitting decat Y piece/ cat removal

Postby kfrogzx7 » Sat Apr 28, 2018 7:10 pm

This worked for me :

Remove rear whl and shock
Remove number plate holder / light from the silencers
I removed all rear bodywork incl indicators for better access and to prevent anything getting damaged
Disconnect the lambda sensor wire at the connector on the right side of the tank ( yep the whole frg has to come off )
Remove the 4 x M6 allen bolts that hold the cat to the headers, several will probably shear so have good quality replacements pre ordered along with 2 new exhaust header to cat gaskets
No need to touch any of the exhaust clamps at this stage because the whole lot will come off rearwards in one go
The silencers are located ( very tightly on two rods ) in rubber bushes, these come apart as you wriggle / lever / bash them rearwards
The cat is likewise supported on two rubber bushes that also allow rearward removal
Pay attention to the lambda wires so that they don't snag anywhere

Once it's all off you can remove the lambda from the cat and the silencers from the exhaust pipe much more easily
Hacksaw clamp bolts is best

Again new quality stainless exhaust clamps are worth having ready

Reassembly is a reversal of this process :roll:

I hate it when manuals say this .... after such a performance to get it off it is always going to be much harder to replace .... sorry.
Simon.
R1100s, R1200st, R1150rs. K100rs.

England
kfrogzx7
Posts: 235
Joined: Tue Jul 15, 2014 9:25 pm
Location: Suffolk

Re: Fitting decat Y piece/ cat removal

Postby kfrogzx7 » Sat Apr 28, 2018 7:17 pm

Oh, I'd forgotten the cat support bracket that has to be unbolted underneath, obviously, before anything will move.
I think it's three 13 mm hex bolts ?
I might have missed some other steps, I'm wracking my brains .... but anyway, that's the general drift of it.

Good luck , it will be worth it I'm sure.
Simon.

R1100s, R1200st, R1150rs. K100rs.

User avatar Great Britain
sjrainsford
Posts: 70
Joined: Sun Sep 24, 2017 11:44 am
Location: Lichfield

Re: Fitting decat Y piece/ cat removal

Postby sjrainsford » Sat Apr 28, 2018 7:23 pm

Thanks for the replies. After having a poke around with a torch I'd kind of presumed the back boxes were just hanging so need to be knocked out.
Yes the bolts that connect the headers to the cat came out no problem. The nut that holds that silly strap that connects the cat pipe to the back box pipe wouldn't budge so I ended up cutting that strap.
I'll have a go at knocking the back box out when I've built up the inclination.
2001 BMW R1100S (Merecat)
2008 Vespa GTS300 (Bianca)

User avatar Great Britain
sjrainsford
Posts: 70
Joined: Sun Sep 24, 2017 11:44 am
Location: Lichfield

Re: Fitting decat Y piece/ cat removal

Postby sjrainsford » Tue May 01, 2018 8:23 am

Again, thanks for the replies. The use of a mallet got it shifted. So I now have a few questions specific to the Danmoto Y pipe. I'd say the fitting isn't too bad, however I'm not happy with the poxy mounting bracket. Almost doesn't seem worth having, what have others done with this fixing?

I've noticed that the tube diameter of the pipe where it slides into the socket pipe on the back box is a little small so cannot clamp down onto it. What have others done to combat this and get a good seal? I've considered putting slits in the back box pipe so that it has freedom to clamp down smaller. Or using something to pack the gap.
2001 BMW R1100S (Merecat)
2008 Vespa GTS300 (Bianca)

User avatar Great Britain
Boxered
Route Master
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Location: Sintelinns

Re: Fitting decat Y piece/ cat removal

Postby Boxered » Tue May 01, 2018 11:06 am

The Laser Y-Piece had the same issue, most people used a shim cut from a drinks can, Pepsi Max IIRC is the exact fit.

Steve
Well-weathered leather
Hot metal and oil
The scented country air
Sunlight on chrome
The blur of the landscape
Every nerve aware

User avatar Great Britain
sjrainsford
Posts: 70
Joined: Sun Sep 24, 2017 11:44 am
Location: Lichfield

Re: Fitting decat Y piece/ cat removal

Postby sjrainsford » Wed May 02, 2018 6:38 am

Actually, I was thinking along the lines of cutting up a drinks can. Thanks Steve. It's just interesting to hear how people have overcome it in the past. At least it's thin enough to cut with decent scissors, so easy to shape.
2001 BMW R1100S (Merecat)
2008 Vespa GTS300 (Bianca)

Neil178
Posts: 648
Joined: Sun Aug 29, 2004 11:24 pm
Location: East Mids

Re: Fitting decat Y piece/ cat removal

Postby Neil178 » Wed May 02, 2018 3:05 pm

Ah yes, that was the other reason to have chilled the beers ...


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