Way to quiet 50 exhaust?

JJScoot · Post by **JJScoot** » Sat Aug 12, 2017 1:50 am

Is there a way to modify or replace exhaust to reduce 2t tinny sound?

Post by **jrsjr** » Sat Aug 12, 2017 3:28 am

2T exhaust design is sort of a black art that goes back well into the twentieth century. Lots of folks tried lots of ideas but eventually it was discovered (and there is a long backstory to this that involves communism, the iron curtain, and Grand Prix motorcycle racing) that the most efficient design was to establish a standing wave that efficiently scavenges spent exhaust gas from the cylinder on the exhaust stroke. The "tinny" sound is the sound of exactly that happening. If you tinker with it, you'll just end up robbing the motor of power.

My best suggestion is to think of it as the music of the spheres, the auditory evidence of pure mathematical perfection at work...

sc00ter · Post by **sc00ter** » Sat Aug 12, 2017 3:29 am

Crazy talk, as thats what gives a 2 stroke its charm! Now, if its a stock exhaust Im not sure what else can be done as they are sealed so repacking is not a option. If its a aftermarket exhaust that can be opened up just repack it. Cycle Gear stocks repack material for 2 strokes exhaust. Here are some suggestions that might help. Use header wrap and wrap from the cylinder flange down to where the muffler starts. Get the wrap wet, as its really messy! And wrap it as tight as possible. Use metal zip ties to secure both ends when done. You could also use sound deadening, like what you put inside car doors when upgrading door speakers, under the panels in as many places around the whole exhaust system. We do this around pod air filters as they can be almost as loud as the exhaust system. Final option is a silent pro type exhaust system by Tecnigas. I use a silent pro street on my 70cc Zuma and its very quiet and allows a bit more airflow. Only downside is they do eventually get louder over time as the inside sound proofing breaks down and you cannot rebuild them. Oh, and a bonus is they look factory and are very durable! Try the header wrap and sound deadening sheets first and see if that helps. I try to keep my 70cc Zuma quiet as possible so I know where your coming from!

JJScoot · Post by **JJScoot** » Sat Aug 12, 2017 11:22 am

jrsjr wrote:2T exhaust design is sort of a black art that goes back well into the twentieth century. Lots of folks tried lots of ideas but eventually it was discovered (and there is a long backstory to this that involves communism, the iron curtain, and Grand Prix motorcycle racing) that the most efficient design was to establish a standing wave that efficiently scavenges spent exhaust gas from the cylinder on the exhaust stroke. The "tinny" sound is the sound of exactly that happening. If you tinker with it, you'll just end up robbing the motor of power.

My best suggestion is to think of it as the music of the spheres, the auditory evidence of pure mathematical perfection at work...

Eloquently stated. Thanks for the reply!

JJScoot · Post by **JJScoot** » Sat Aug 12, 2017 11:24 am

sc00ter wrote:Crazy talk, as thats what gives a 2 stroke its charm! Now, if its a stock exhaust Im not sure what else can be done as they are sealed so repacking is not a option. If its a aftermarket exhaust that can be opened up just repack it. Cycle Gear stocks repack material for 2 strokes exhaust. Here are some suggestions that might help. Use header wrap and wrap from the cylinder flange down to where the muffler starts. Get the wrap wet, as its really messy! And wrap it as tight as possible. Use metal zip ties to secure both ends when done. You could also use sound deadening, like what you put inside car doors when upgrading door speakers, under the panels in as many places around the whole exhaust system. We do this around pod air filters as they can be almost as loud as the exhaust system. Final option is a silent pro type exhaust system by Tecnigas. I use a silent pro street on my 70cc Zuma and its very quiet and allows a bit more airflow. Only downside is they do eventually get louder over time as the inside sound proofing breaks down and you cannot rebuild them. Oh, and a bonus is they look factory and are very durable! Try the header wrap and sound deadening sheets first and see if that helps. I try to keep my 70cc Zuma quiet as possible so I know where your coming from!

Thanks. I'll look into that muffler. Will try the wrap in the meantime.