Spark Arrester Help

Per the SAE testing procedure it is ok to use a spark arrester on an engine smaller than the one it was tested for. If the outside dimensions of your muffler are simular to stock a sparky should work. Without an angled pipe it will just send the exhaust around the edge more but it still has to go through the screen which ensures that large carbon particals can't excape.

Just order another silencer from FMF that already has a sparky incorporated into the design. I think they call them TURBINE CORE`s. It should be under your $140.00 dollar limit.

mxbundy

I would call FMF and see what they can do. I've got a turbine core on my KTM, and it rocks!

I can see two possibilities for you. You can take your muffler down to your local motorcycle shop and see if you can find a Sparky that will fit it. If you are concerned about the angle that the newer sparkys make you can attach a piece of curved hot water rubber hose to the end of your exhaust outlet. The rubber hose will probably last a season. This is probably the best plan because the enforcement officer will see the USFS approval and ok you. Another approach would be to obtain a screen with less than .023” openings and attach it to your exhaust opening. You would need to have 4 times the exhaust pipe area in screen. This technically is ok because it complies with the intent of the law, however it has some draw backs. Such a device is not registered with the USFS and your local enforcement officer may not see the logic of complying with the more stringent requirements of a saw. I have discovered that such screens are used in “high end” cooking strainers. Measure the screen opening with a wire feeler gauge. Check out this web site.
http://www.fs.fed.us/im/directives/field/r3/fsm/5100/5110.txt