Zongshen 200GY-2: FMF Silencer Modification

[SpudRider]

I love the FMF Universal Spark Arrestor I installed on my Zong five years ago.

http://www.chinariders.net/showthread.php?t=5974



However, the hot exhaust gasses exiting the silencer have claimed several vicitims. The first casualty was the reflector located right behind the muffler, which disappeared shortly after the silencer was installed. Other victims have included several rear turn signals, which were weakened by the hot exhaust gases, and eventually broke at the stems.

After the last turn signal broke, I decided to fix this problem by installing a pipe to deflect the exhaust gasses downward, away from the motorcycle. I went to Lowes (hardware store) and purchased a 1-1/4" copper elbow with a 'street fitting.'

http://www.lowes.com/pd_73422-137-CL...bow&facetInfo=



Removing the bolts from the muffler's endcap, I used a slide hammer to separate the end cap from the FMF silencer. Using an angle grinder, I cut the copper elbow to a 45-degree angle. I also trimmed the narrowed opening on the muffler's end cap to enlarge it enough so I could insert the copper elbow inside.

I then coated the smaller diameter of the elbow with VersaChem 650 High Temp Red Silicone, and inserted the elbow inside the tube of the muffler's end cap.

http://www.oreillyauto.com/site/c/de...1786&ppt=C0050



Next, I drilled four holes through the end cap's inner tube and the copper elbow; each hole was spaced 90 degrees away from the others. I then placed four, 3/32" rivets in each hole to secure the end of the elbow to the tube inside the muffler's end cap.

I let the high temp silicone cure for 16 hours, then I re-assembled the muffler. Here is how the muffler looks with the elbow gas deflector installed.







The FMF silencer is now a little quieter with the exhaust gasses deflected downward toward the pavement. More importantly, the hot gasses are now deflected away from my rear turn signal. I am very happy with this modification.

[Weldangrind]

Great idea!

The copper might not get that wonderful patina that eventually occurs, since hot exhaust is introduced. The elbow looks really good, as if it came from FMF that way.

[SpudRider]

Thank you, Weld. The elbow looks good, sounds great, and directs hot gasses and soot away from the bike; I am very pleased with it's operation.

[Weldangrind]

I might make a similar mod to see how it affects sound. I want to open up the XR250L muffler I installed on my Lifan.