Sound Testing

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AJRJ
2024 RMDRA Member
2024 RMDRA Member
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Re: Sound Testing

Post by AJRJ »

Well, it depends :D

Some 450s are quieter (Honda) or louder (Kawasaki) with KTMs somewhere in the middle? Most bikes should pass the FIM test that's randomly employed now.

For the spark arrestor it is not required to deviate from stock, but encouraged. We all want to be responsible in our new environment of extreme scrutiny. Consider the use of a FMF Q4 or similar if possible.

:thumbsup:

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malcolmzilla
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Re: Sound Testing

Post by malcolmzilla »

2015 YZ250FX stock exhaust FAILED Idaho City 100 testing in 2016, USFS 96dba limit I believe.
This is the "euro" mx can on the FX models, so is supposedly quieter than North America MX version (YZF).
15 Yamaha YZ250FX, 270cc, cams
15 XC250
11 Berg 570, dualsport and supermoto
17 PW50
78ish CT70
Just another Dirt Donkey...

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malcolmzilla
2024 RMDRA Member
2024 RMDRA Member
Posts: 879
Joined: Fri Jun 26, 2009 11:14 am

Re: Sound Testing

Post by malcolmzilla »

Idaho city 100 they place a microphone by exhaust blip throttle. Spark arrestor test is rod inserted into pipe to see if it stops before full insertion.
15 Yamaha YZ250FX, 270cc, cams
15 XC250
11 Berg 570, dualsport and supermoto
17 PW50
78ish CT70
Just another Dirt Donkey...

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AJRJ
2024 RMDRA Member
2024 RMDRA Member
Posts: 1185
Joined: Sat Jun 26, 2010 1:45 pm

Re: Sound Testing

Post by AJRJ »

The FIM recommends the "2 metre Max" method.

The mic is 2m away from the exhaust outlet at 45 degrees, and the motorcycle is help at max RPM for 1 second.

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