braddon Posted October 19, 2009 Report Share Posted October 19, 2009 I went to my first trial yesterday and several people commented on how loud my bike was. I didn't notice it until then but now it is rather loud compared to all the other trials bikes there. I Was told it would be a good idea to pack the exhaust tighter, i did this a few months ago but still took it all out and did it tighter. I managed to fit a lot more packing in doing it as compact as i could. Its still just as loud after doing this though. Any suggestions on what i could to to quieten it? Thanks Quote Link to comment Share on other sites More sharing options...
chewy Posted October 19, 2009 Report Share Posted October 19, 2009 Never done a Beta but most bikes have a baffle tube (perforated) if this is clogged up with carbon & oil gunge which is possible it wont allow the sound to be absorbed and thus dissipated. The bike will ride better too if you get it right. Quote Link to comment Share on other sites More sharing options...
wherry Posted October 19, 2009 Report Share Posted October 19, 2009 I Was told it would be a good idea to pack the exhaust tighter, i did this a few months ago but still took it all out and did it tighter. I managed to fit a lot more packing in doing it as compact as i could. Its still just as loud after doing this though. Any suggestions on what i could to to quieten it? Yes. Take out the packing and either put some of it or some new stuff in quite loosely after making sure the tube is clean as Chewy says. You want the packing to fill the available space around the perforated tube but definitely not to be wedged in tightly otherwise it won't absorb the sound as you have found. Should soften up the power a bit. Quote Link to comment Share on other sites More sharing options...
braddon Posted October 19, 2009 Author Report Share Posted October 19, 2009 Yeah the tube is clean i cleaned it out with a wire brush and blow torch when i repacked it to get all the carbon off. So i need to pack it again but not tightly just to fill the space? This could be where i am going wrong as it is as tight as i can get it at the moment. I was told you can use fibreglass roof insulation for it as i have run out of the proper stuff, is this correct and will it affect performance etc at all? Thanks Quote Link to comment Share on other sites More sharing options...
wherry Posted October 19, 2009 Report Share Posted October 19, 2009 Yep loft insulation is OK - that's what I've got in mine at the moment. I used some of the slab stuff like they put between the walls of new houses, but you could use any of the roll types I should think. You need to fill the exhaust with loosely packed insulation. If you find yourself ramming it in with a piece of wood it's too tight. I did mine twice before I was satisfied with the result. The other option, of course, is to get a replacement packing from Lampkins that should be just right. Quote Link to comment Share on other sites More sharing options...
braddon Posted October 19, 2009 Author Report Share Posted October 19, 2009 thanks will give it a go tomorrow. cheers Quote Link to comment Share on other sites More sharing options...
braddon Posted October 20, 2009 Author Report Share Posted October 20, 2009 i just repacked it but quite loosely this time and not too tight. to be honest its no better. any other siggestions or do i just have a noisy rev3? Quote Link to comment Share on other sites More sharing options...
wherry Posted October 20, 2009 Report Share Posted October 20, 2009 Are there any O-rings or other seals on the Rev exhaust where it could be leaking? Do you have to seal the end on with silicone when you've repacked it? Maybe you can feel with your hand if it's leaking anywhere where it shouldn't be. If it's leaking it won't help, of course. If you can't find anything wrong I'd experiment with different amounts of packing, including none to get a feel for how much you're quietening it, and then once you've found the best amount seal it up with some silicone sealant. Maybe give Lampkins a ring to see what they say? Quote Link to comment Share on other sites More sharing options...
braddon Posted October 20, 2009 Author Report Share Posted October 20, 2009 cheers will have another tinker tomorrow. Quote Link to comment Share on other sites More sharing options...
wruffit Posted November 27, 2011 Report Share Posted November 27, 2011 Hi, you have the same problem as me and it does not seem to be easy to fix! I have two 2008 270 Beta Rev 3's, one has clearly been abused and is very loud, the other is 'as new' (still on original tyres) and this one sounds lovely. I swapped the mid sections around and the 'dog' sounded lovely too... The two centre boxes are totally different weights so I can only draw conclusions that it is really chocked up... and here lies my/your challenge. I tried burning it out yesterday with petrol (do a search) but it seems no better. I am a bit lost what to do... Hopefully an exhaust guru will come along and help out... who knows maybe someone will even offer a mid section repair service... See ya Quote Link to comment Share on other sites More sharing options...
wruffit Posted November 27, 2011 Report Share Posted November 27, 2011 Brief update! Had another go this morning and a better result (but not perfect). I got the exhaust much hotter by filling with petrol, draining and then burning it out three times. The temp went well over 100 degrees centigrade so I has plenty of water on hand to cool the metal work whilst blasting air in from my compressor. I could see the 'burn' had worked in much of the box (but not all) because the inner baffle was burned clean (ie no carbon deposits, dirt or otherwise) You can tell if the gunk is burning by a dark grey white smoke that doesn't smell like petrol.. (the petrol burning off will just be a black sooty smoke) Could probably do better but maybe next year. Definately better but as above not perfect. See ya Quote Link to comment Share on other sites More sharing options...
madmostin Posted November 29, 2011 Report Share Posted November 29, 2011 gonna give this a try. my friend has a beta and its rum pop pop rum pop noise is so much louder than others i know of. think previous owner ran it at 30-1 ! Quote Link to comment Share on other sites More sharing options...
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