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sound tests at CCC events (tomahawK tour)

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How strict are they on the sound test?

Last year with a stock pipe and PMB sparky, I supposedly passed on my crf450. While my friends with a stock yz426 and a wr250 didnt. They just told them/warned them and let them ride anyway.

Now I have a Big GUn slip on (somewhat louder than stock) with a sparky. Will they give me a hassle? Should I just put on the stock pipe for the weekend?

Do those PMB quiet inserts significantly affect the bikes power?

We wont be getting there till around 3, so I dont want to mess around with it when I get there.

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At the R.O.S this year the tried to fail my DRZ with a stock can on it. said it fell just under at 93.6db but last year it was 82db. I think it depends on who you get running the equipment (read: someone that knows what theay are doing)and who has pissed in their cheerios that day.

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I helped at sound test at the fall color tour last year. Any aftermarket exhaust brings out the sound meter. The promoto ones all seemed to be running loud. They seemed to give around a 1db leeway. So if you came in around 95-95.5db they would let it fly with a warning. But if you hit 96 they usually had to go fix it somehow.

A friend of mine had that Big gun on his CRF450 and couldn't get it past sound test. Ended up sending it back.

The only thing that would pass without question is a stock XR/CRFX exhaust, a stock KTM exhaust, the stock WR exhaust, stock DRZ or a FMF turbine core silencer on the 2-strokes. Any other silencer would be in question. Basicaly if its a offroad bike (not a MX bike) the stock exhaust will get you thru. If its aftermarket exhaust they are probably gonna check it.

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Thanks YZman, I think I will put the stocker back on along with the quiet insert. If it runs to crappy with the insert, I can always pull the restricter out after testing.

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I put my stock exhaust on my X for the CCC events instead of my FMF Q. I had the Q tested last year and it just squeeked by. I figure that runing the stock exhaust for one weekend wont kill me, regardless of how choked up the bike may be. Its only one day then I can change it back out. At least with the stocker on they dont even give it a 2nd look.

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hopefully with the stock crf with PMB silent insert& sparky I wont have any probs passing the test. PMB advertises that it takes it at least down to 96db with the insert.

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The only thing that would pass without question is a stock XR/CRFX exhaust, a stock KTM exhaust, the stock WR exhaust,.....

I couldn't believe my newer, stock WR 250 failed last year.... :)

I'll probably just insert the baffle for the test and pull it out once I'm on the trail....

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I couldn't believe my newer, stock WR 250 failed last year.... :)

I'll probably just insert the baffle for the test and pull it out once I'm on the trail....

I am guessing that the removal of the stock baffle was your problem. The WR's are a tad loud with the insert removed. Drill a few holes in the end cap of the stock insert to let it breath a little more. But not enough to let it bark. That should help some. Yamaha makes a GYT insert for the WR exhaust.

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Nag mode on/

Loud bikes close riding areas & trails plus they piss off the non-riding public and screw us for other riding related opportunities ala open county roads.

Do everyone a favor and keep it quiet.

And here's a promise - anyone caught "switching pipes" after passing sound check will be removed from the event.

For this particular ride we lost 4 miles of fantastic dual sport because of a freaking hawk's nest. On the Rites of Spring the USFS blocked us from using a Forest Road that was near an Eagle's nest and went on about how limiting our noisy machines were in which areas we could use.

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Dont get me wrong I totaly agree in quiet bikes. But I aint no saint either. I aint gonna run a 89db bike when they will let me have a 94db. I like power as much as the next guy. An that stock exhaust at 89-90db on my X is just waay to restrictive. If my Q passes at 94db Ill take it.

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I am guessing that the removal of the stock baffle was your problem. The WR's are a tad loud with the insert removed. Drill a few holes in the end cap of the stock insert to let it breath a little more. But not enough to let it bark. That should help some. Yamaha makes a GYT insert for the WR exhaust.

Yeah, I even had the GYT insert in my bike. Still didn't pass. I guess I'll try to pass it this year as is.....stock exhaust and GYT insert......hopefully, the guy last year was just not accurate with his test.

I'll try drilling a few small holes in the end cap, too.

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The GYT insert on a Yamaha WR pipe should test at about 92db. Stock baffle mid 80's. Stock pipe without baffle about 100db. Decibles are not a percentage, 100 is not 6% louder than 94. Sound doubles every 6 db., so 100 is twice as loud as 94. Sound is a big issue for off road events (CCC rides, Enduro's etc.) Pressure is mounting and organizers will send you home if you don't meet the 94db limit. If they don't permits for future events will dry up. Lets keep em quiet, a responsibility shared by all of us. :)

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Just watch out that drilling holes dosn't void the spark arestor in the exhaust. I think the spark arestor is in the can not in the insert. But something to look into. You dont want someone telling you that its not spark arested cause you drilled a few holes.

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You know some thing that I was wondering at the Color tour. When they are testing a bike they make sure that there is no bikes behind you for like 20 ft. But what about all the bikes running up and down the 2-tracks in the area. There is a lot of back ground noise in the area. How does this affect the test?

You know something else that I was wondering about. They are supposed to test at what, 1/2 max rated rpm, 20" @45deg right? I was watching them with that vibration tach thingy barely putting any rpm to the bikes when they tested them. There aint no way that they were running them up to 1/2 max. Them bikes would be roaring. The new 4-strokes redline at what 12,000 rpm. Aint no way they were testing them at 6,000rpm. Heck the 2-strokes I saw them test were barely off idle.

Dont get me wrong. Lower test rpm works in our favor. It just puzzled me a little while watching them test the bikes last fall.

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The GYT insert on a Yamaha WR pipe should test at about 92db. Stock baffle mid 80's. Stock pipe without baffle about 100db. Decibles are not a percentage, 100 is not 6% louder than 94. Sound doubles every 6 db., so 100 is twice as loud as 94. Sound is a big issue for off road events (CCC rides, Enduro's etc.) Pressure is mounting and organizers will send you home if you don't meet the 94db limit. If they don't permits for future events will dry up. Lets keep em quiet, a responsibility shared by all of us. :)

Ok. Based on some other research I was sent, that sounds right. Guess I'll just try it again, unchanged.

If I do fail, will they allow me to throw the baffle in and re-test to ride the event?

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VantolR

If I remember right, I dont think you got that GYT insert until mid-late summer. We did that CCC ride (meadows?) early in the summer. I dont think you had the baffle or GYT in your bike at that time.

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I went to the Mounds last year to do a little test ride. The dnr guy brought out a book and looked up my bike to get the rpm readings. My wr250f just barley squeeked in. FMF Q. I"m taking my cr250 with a fmf q this weekend . I want to see where it tests out at.

My opinion is this: I think as long as a person has made a reasonable effort to quiet his machine and has a spark arrester( any bike can be spark arrested easily) then so what if he blows 95-96. Make this 94db absolute religious law and I think most riders will say "screw it " and not even bother to try. :)

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But what about all the bikes running up and down the 2-tracks in the area. There is a lot of back ground noise in the area. How does this affect the test?

It will increase your sound level; same for ground type/conditions (grass/no grass, sand/pavement, etc.). If you fail sound, then you'd request to be tested under proper conditions. Difficult to have optimal conditions when we are camping in a field.

They are supposed to test at what, 1/2 max rated rpm, 20" @45deg right?

The book has the proper test RPM for each bike, they should have been going by that. The basic idea is half of max RPM or half of max power output, but it's pretty variable. I'd only fuss, like above, if I failed (as you implied).

I have the book and meter in my rig right now; glad to look up a couple numbers if you want.

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It will increase your sound level; same for ground type/conditions (grass/no grass, sand/pavement, etc.). If you fail sound, then you'd request to be tested under proper conditions. Difficult to have optimal conditions when we are camping in a field.

I was just curious. Has anyone ever tested there bike in ideal conditions ie dead quiet. Then again at an event with all the back ground noise. Just curious what the diff would be. Not that I am complaining about the testing process, these are just observations that poped into my head. Ya know us engineers cant stop thinking :):D

The book has the proper test RPM for each bike, they should have been going by that. The basic idea is half of max RPM or half of max power output, but it's pretty variable. I'd only fuss, like above, if I failed (as you implied).

I have the book and meter in my rig right now; glad to look up a couple numbers if you want.

They were using the book and the vibrating wire thingy at the color tour. But like I said it really didn't seem like the bikes were 1/2 max rpm. Every bike tested seemed to be more like 1/8 rpm. But like I said that would work to our favor. Less RPM = less sound = more passed bikes :)

What would the test RPM be for my CRF250X?

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Will look up numbers when I find my way home...

Just noticed your member status (bronze/gold/); jeez that's funny!

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