Alternative silencer

Just wondered if the tuned length of an expansion chamber included the silencer length also. I am looking to fit a Tecnigas RS180 carbon muffler to the JL3 on my lammy (yep modification will be required). This pipe can be used on Gilera 180 so shouldn’t restrict the mugello 190. OR WILL IT ?

Please don’t go all LCGB on me stating „this is a vespa forum“ as some nuggets are known to do [:D]

Hi mate,
the lenght of the chamber expansion is one thing and the length of the terminal tube is another one. But modifying the lengthof the terminal tube (silencer included) you also modify the performances. Adding or cutting 10 cms can change the performances of the bike. My personal experience is that if you have a slight difference such as 1 or 2 cms you don’t feel any difference in the behaviour of your bike.

Just been and got it the bottom paragraph says a bit about the tail can
http://www.southernskies.net/page_info/runningtwostrokeengine.html

As a matter of interest, roughly how long is silencer on your setup and whats the rough diameter of the stinger. Appreciate its a suck it and see scenario, so ideally will have to find something that mirrors JL proportions.

Hi my JL3 has a tail pipe off an unkown motorcyle after market pipe. Got from a mate and I think it was off an aircooled RD. It allowed the bike to rev on on the motorway past the normal ceiling of 8000ish rpm JL3 usually allow. Its very long and I have to say quite ugly but it improved performance. This is on a TS1 with 16 47 sprockets. Its a suck it and see thing but the tail pipe length and the diameter of the stinger has a definite effect. It was also a massive improvement on the fall to pieces tail can that comes with all JL pipes. The tuned length doesn’t include the tail can but does effect the charateristics. If you go on the LCGB site someone has posted some info on this.