GS 425 - What size slip on muffler?

[Spikus]

I have a 79 GS425 that I'm converting to a cafe racer. I scored a great deal on here for a complete almost new stock exhaust, but the mufflers are way too long for what I'm going for. I want to cut them off and mount some shorty slip on mufflers that will flow and sound much better. I've found several on Ebay with the look and length I want, but don't know if the mufflers slip inside or over the exhaust pipes. Thinking about the flow, I would think they fit over, but don't know. The muffler manufacturers say they fit a X diameter pipe, but is that inner or outer?

[Big Rich]

They fit over the pipe. I'm not sure what diameter you need for your exhaust though.

Fyi: an exhaust system is generally a tuned length to get the most power at realistic RPM ranges. Too short and you're just losing power.

[Spikus]

Thanks for the info Rich. So I need the outside diameter of my pipe for fitment purposes. I know the components in the stock setup are all designed to work together, but I've already ditched the airbox and am going with Emgo pod filters, so I've already pretty much blown the factory setup. The mufflers I'm looking at will be about 2/3 the stock length, and will be much more open.

[cowboyup3371]

I don't have pods but there are plenty of threads on here that state those Emgos are crap. Spend the money on K&Ns and search for rejetting threads as you'll have a lot of work to do to get them running right.

[Big Rich]

+1 about the Emgo pods.

There are quite a few places around that explain why the Emgo pods are just terrible. Basically, the rubber lip on the inside blocks off a necessary passageway on the carbs.

[Spikus]

Thanks for the info Rich. I bought the K&Ns ...

[pete]

Good stuff, K&N's rock