Do Gen1 and Gen2 share the same after market slip-ons? I know the OEM mufflers look totally different but can I install, say, Yoshimura for Gen1 on my 2014 ZX14R? My bank account is running out of money and I am opting for an used set of slip-ons.

I've been trying to find the same answer on cans and full systems. According to my "mechanic" buddy at the local bike repair place (he's a very competent and well trained young man), he has looked at the dealer catalogues, and it is his opinion that if the slip on will fit a '12, then it will probably fit a '13 or '14. There are only two 14R's here, my former '13 sold locally, and my new '14. He did a complete Yoshi R-55 on the '13 for the new owner, but otherwise he (and me...) have come to the conclusion that if it's a '12+, it probably will work. We found that most of the catalogues seem to indicate that a '12 or '13 product carries the same product number as the '14 number - when you can find it.

* Last updated by: groomlake on 10/2/2014 @ 5:16 AM *

Gen1 is from 2006 to 2011
GenR is from 2012 to 2015

No Gen1 header fits the R head, as vice-verse.
No Gen1 sip fits an R slip.

Gen1 is from 2006 to 2007 with small diameter mid gaskets
Gen2 is from 2008 to 2011 with the larger diameter ID however both have the same OD so any gen1 and gen2 mufflers fit on gen1-2 headers. Which means, all gen1-2 mufflers fit on any gen1-2 header being they share the same OD to slip on.

Therefore, the gen1-2 headers and mufflers are interchangeable to each other only.
Therefore, genR mufflers and headers are interchangeable to each other only.

GenR grew a mm or two larger at the header spread (no gen1 fits a genR head and vice/verse of that mm spread at the ports. As is the OD of the muffler to the mid-pipe are both different mm sizes too.

Used or new, find any full muffler system or slip that is for the gen1 and gen2 series, but do not buy new/used any slip or header for a gen1 to apply on a genR... Will not fit.

Question: Do Gen1 and Gen2 share the same after market slip-ons?
Answer: Yes. Gen1 and Gen2 fit each other.

Q: ... can I install, say, Yoshimura for Gen1 on my 2014 ZX14R?
A: No. See above description of Gen changes.

Im running 2011 Delkavek slip on on my 2012 R. They went on with little fuss.