My new-to-me 07 KLX250 is all stock. I've been reading up on the exhaust, intake, and jetting mods and I'm eager to get started.

But we have this 96 dB noise law on the trails starting this summer. I'm worried about the slip ons being too loud and getting me ticketed. Does anyone know which ones would be quiet enough? It sounds like the FMF Q4 is about the quietest from what I'm reading.

Another option would be to drill the stock muffler. But would that disable the spark arrestor? I expect the Forest Strangers to be equipped with butt probes as well as sound meters.

thanks,
Debby

 

Hi Debby, I'm interested in the new 96 db law starting this summer. Can you tell me more about that?
I'll be playing in the Estes to Rollins Pass area this summer with my KLX.

Concerning the noise levels. When I drilled the stock muffler it didn't seem to make any performance increase or much noise differences to me. I'm not sure, but I think that drilling disables the spark arrestor. I now have a FMF Q4, and it says it is 96 db max right on the sticker on the can. It is quite a bit louder than the stock muffler, but I do think it is one of the quietest aftermarkets you can get. Another KF member and I did a D/S ride last fall and they had a sound check. Both of us had KLX's, mine with the Q4 and his with the Two Brothers slip on and the FMF P-bomb header. The event organizers couldn't find the KLX 250s in their book of what RPM's to test at. Some how they eventually settled on 3500rpm for testing the klx. At 3500 the Q4 was at 92 db's and the 2 bros was at 99db's. Another member with a stock muffler tested at 88db. All of those sound pretty high to me, especially the stock one. Another option besides the Q4 is the stock KLX 300 muffler. Sometimes you can find them pretty cheap on Ebay. It has a much bigger opening than the stock klx250s.
Hope some of that made sense. Search around on here, lots of info,sometimes it's just hard to find .
Dan

 

Hi Dan, thanks for the info. Sounds like the Q4 might be ok.

The new sound law takes effect July 1. It's probably the same test procedure you guys experienced. They say it's the "SAE J-1287 stationary 20” pipe test". Previous limit was 99 dB, new limit 96 dB. Spark arrestors are also required. In the past I've never encountered any sound testing, but I have had rangers check my spark arrestor and OHV tags. (I also have a Bultaco Sherpa T vintage trials bike in addition to the KLX).

I imagine there will be an initial flurry of enforcement at the more popular areas this summer.

Debby