Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0

Exhaust inquiry...........

1 post in this topic

Hey now-finally a registered participant here. Have been lurking around for some time, great forum!

I'm a YFZ guy (quad), I have a question that maybe someone can help with. I (actually my son) was approached by the boy's in brown (park rangers) at our local OHV park. My YFZ is equipped with the HMF slip on exhaust , and all the jetting that is required. I've also done the cam-mod and I'm quite pleased with all around performance. I took the bike in for a voluntary sound test. It blew 103db with just the spark arrestor and 100db with the quiet core I purchased when I bought the pipe. California is 96db-so I got a problem. The park rangers were quite cool about the whole situation. They kinda hinted around about a local guy (yamaha mechanic) that was doing r/d on exhaust's for the WR and YZF bikes. Said he had come up with a can from the KTM open class bike, and fabbed it up to work on the yamaha bike. Was right on the db acceptance level, but suffered no loss of power seen with acceptable db output.

I just wanted to throw this out there, since I really don't want to give up any extra hp that I've worked so hard to achieve. I do know that more power usually means, more sound. I ride alot of the OHV parks here in CA, so need to stay legal.

Sorry for the long first post.....kinda complicated.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
Followers 0