Katana Owners Club U.K.

I just purchased a set of centre downpipes for my Pop up.
Just received and find that the clamps are missing and the collets don’t seem to be right
Could somebody tell me what should be fitted

Can't remember what mind look like , will look at weekend, for now measure the diameter , the pop up is less than the S1/2. Which these could be ...GSX 750 1983 could be either if you didn't know so could have been wrongly marked up.

Pop Ups have captive clamps on centre pipes that don't come off.. they're put on at manufacture.

You'll have to manufacture some collets and find some clamps, obviously.

I recently had to buy a whole bike just for the centre downpipes.. proper hen's teeth, so I'm amazed you found a dent and rust free set.

Yep , the clamps are on the downpipes on the ES/SE ...Those on the S1/2 are in 2 halves .
Which is why I suggest measuring the diameter before you go further . It could be that these are pop up ones but some muppet has cut off the clamps to get it off the bike OR it never had any because it's not the correct one.

I have checked the collets and as you suggested they are very slightly larger than the exhaust port
The pipe centre line up to the engine so I am wondering if I can just remove the existing collets and replace

This would suggest that this exhaust is incorrect , so filing the collects is only the start of your problems / project.. Next will be the bends will be different ....then of course the diameter means it won't fit into the collector as it will be wider on the bike .

I think I will need to try and source an aftermarket exhaust to at least get me back on the road

You have options
1. You will need to paint them but they will fit and do the job .. They will accept offers and if you phone them you'll be able to haggle a bit.
https://www.ebay.co.uk/itm/Suzuki-GS750 ... SwFwBfjwXU

2. https://www.ebay.co.uk/itm/System-Of-Ex ... Sw2PVfwS-p
The only new 4-1 available at the moment , although Preditor do one at £500 .
Depends on if you are just after riding or restoring it to a standard where it's to clean to ride!

OR fit this and no need to paint , or paint all the same .
https://www.ebay.co.uk/itm/Suzuki-GSX75 ... Sw~f9fQTTL

Even https://www.ebay.co.uk/itm/Suzuki-GS700 ... #vi-ilComp
Costly though!

If it will help , I have a Marshall 4-1 in my garage you could borrow , it is my spare system as both my pop ups have 4-2 on ( 1 is a GS700 system from a calafornian bike like the last link above really )
But I would like to have the option in the future should I need it...
However at the moment it ain't being used and if it helps a club member get mobile again, then if you can collect it your welcome to borrow it.

Thanks for the offer it very much appreciated but I have managed to borrow a well used Motad system