spokerider Posted March 2, 2009 Report Share Posted March 2, 2009 Did a search, still have a few questions please.......... I'm trying to clean the exhaust silencer on the 348. Tried the caustic soad soak x 24 hours......very little if any grunge came out. Still looks oily inside. What is inside a 348 silencer for packing? Thinking of trying a propane torch and burning any crud out. Seems others have cut through the silencer and replaced packing material.......but on a 348?? Not wanting to spend $200 plus on a new one at this time. Thoughts? Want to paint the exhaust system with high temp black paint following cleaning. Quote Link to comment Share on other sites More sharing options...
02-apr Posted March 2, 2009 Report Share Posted March 2, 2009 Back in the day I cut a flap in the back of both the main and tail silencer, took out the old fibreglass packing and replaced it with new before welding back up. It certainly made the bike a lot smoother and allowed better tight turns - remember nobody used the clutch in those days. Quote Link to comment Share on other sites More sharing options...
spokerider Posted March 3, 2009 Author Report Share Posted March 3, 2009 Back in the day I cut a flap in the back of both the main and tail silencer, took out the old fibreglass packing and replaced it with new before welding back up. It certainly made the bike a lot smoother and allowed better tight turns - remember nobody used the clutch in those days. Thanks for the reply. I tried burning out the oil residue with a propane torch for 40 mins today, as well as the soda soak yesterday. I'll see how that goes, if not sufficient, I'll cut out a flap, re and re the packing and weld it back up. It likely never been done before, so it can only help rule out any exhaust / constriction complications. Quote Link to comment Share on other sites More sharing options...
bigshineybike Posted March 14, 2009 Report Share Posted March 14, 2009 Can you over pack the rear box? My 348 sounds awful, far too 'tingy' for my ears. Someone did come over to me and say how he enjoyed hearing an old mont again but I dont think its right. I cut the box open expecting to find it empty but it is hard packed with fairly clean looking fibreglass wool. Is it so tighly packed that it cannot absorb the shock waves? I still havent met a 348 owner while my biuke has been running so dont really know what it should sound like. Thanks Quote Link to comment Share on other sites More sharing options...
wayne_weedon Posted March 14, 2009 Report Share Posted March 14, 2009 It may look clean, but at the core immediately around the perforated tube it will probably be solid. Once all those little holes block up it becomes a straight through system with nowhere for the gas to expand. I recently did a Sherpa Clubfoot silencer and that looked clean on the outside of the packing. Not so in the middle. Wayne.... Quote Link to comment Share on other sites More sharing options...
spokerider Posted March 15, 2009 Author Report Share Posted March 15, 2009 Well I cleaned the rear silencer with the lye / water mix and then used a propane torch to burn all the oil residue from the thing. Lots of stinky smoke....... Anyway, it sure "breathes" well without any constriction when I blow air through it. A question about the glass packing.........is it there strictly for "silenceing" the sound or does it have a purpose having to do with backpressure and correct engine breathing etc? How large of a flap of the silincer needs to be removed to gain access to the inner old glass packing to remove and replace? Is the effort worth the benift? Anyone have a pic to share? I'm at the stage of sanding and about to paint the exhaust....... Quote Link to comment Share on other sites More sharing options...
spokerider Posted March 17, 2009 Author Report Share Posted March 17, 2009 Today I cut a flap of metal from the back side of the 348 silencer with a grinder and thin cut off wheel. Not a thread of glass inside, and it was fairly clean inside with all of the lye and burning I'd previously done to it. Packed some woodstove fiberglass door seal into and around the baffle tube and replaced the flap with a piece of .050" metal. Mig welded it up and ground the welds down flush with the grinder. You can barely tell it's been opened....... Only took a few hours total to complete and seems to be time well spent....... Quote Link to comment Share on other sites More sharing options...
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