usafstud Posted March 13, 2011 Report Share Posted March 13, 2011 Hi,I'm wondering what you guys think about the (penny) tingng noise of my 1972 Yamaha LS2 is making.I don't know if this is normal or not. I going to start commuting with it again and my wife is planning on doing the Lake Eeri loop event with me on the bike.1972 Yamaha LS22stroke100ccThe only mod i have done is taking out the baffle packing to it.http://s96.photobucket.com/albums/l200/usaf060stud/?action=view¤t=4fccdf4f.mp4Thanks,Frank Quote Link to comment Share on other sites More sharing options...
Jcarlson Posted March 23, 2011 Report Share Posted March 23, 2011 Bad valve? Just guessing. Nice ride BTW!! That's sharp for its age. Quote Link to comment Share on other sites More sharing options...
Strictly Street Posted March 23, 2011 Report Share Posted March 23, 2011 Hard to tell from the video.http://www.cmsnl.com/yamaha-ls2-1972_model8408/partslist/ Quote Link to comment Share on other sites More sharing options...
dorifto240 Posted March 26, 2011 Report Share Posted March 26, 2011 (edited) Apart from being an actual penny?Maybe it's just something around the engine that has come loose and is rattling.Or it's CLEARLY NOT the valves. Or maybe the ignition wires are arcing somewhere? Edited March 27, 2011 by dorifto240 to save face and avoid punching myself in the nuts. Quote Link to comment Share on other sites More sharing options...
DAC Posted March 27, 2011 Report Share Posted March 27, 2011 Everyone that suggested it's the valves.. please punch yourself in the testicles' date=' right now. That engine sounds fine to me. You're most likely hearing internal engine noise being amplified off the cooling fins on the engine. Don't sweat it.[/quote']:lol: Quote Link to comment Share on other sites More sharing options...
ReconRat Posted March 27, 2011 Report Share Posted March 27, 2011 If it goes away or gets less when it warms up, I'd say it's the piston, rings, and cylinder wall. Those can make a ringing or bell like sound, particularly when cold. There's a lot of expansion on 2-strokes. It's all the heat generated from double the power stokes. They can be pretty loose when cold. Worst case would be stuck rings or worn piston skirt, but I'd think it would start smoking out the tailpipe with that.edit: And yeah, it doesn't sound bad from the video. Just louder than normal maybe. Quote Link to comment Share on other sites More sharing options...
chevysoldier Posted March 27, 2011 Report Share Posted March 27, 2011 There's a midget with a hammer inside. Quote Link to comment Share on other sites More sharing options...
oldschoolsdime92 Posted March 27, 2011 Report Share Posted March 27, 2011 Bad valve? Just guessing. Nice ride BTW!! That's sharp for its age. You gave me a good laugh though! Quote Link to comment Share on other sites More sharing options...
usafstud Posted March 28, 2011 Author Report Share Posted March 28, 2011 If it goes away or gets less when it warms up, I'd say it's the piston, rings, and cylinder wall. Those can make a ringing or bell like sound, particularly when cold. There's a lot of expansion on 2-strokes. It's all the heat generated from double the power stokes. They can be pretty loose when cold. Worst case would be stuck rings or worn piston skirt, but I'd think it would start smoking out the tailpipe with that.edit: And yeah, it doesn't sound bad from the video. Just louder than normal maybe.i do get a bit of white smoke Quote Link to comment Share on other sites More sharing options...
Strictly Street Posted May 8, 2011 Report Share Posted May 8, 2011 i do get a bit of white smoke2-strokes do smoke normally. White-blue smoke is very normal.No smoke and you might want to think about adding a bit more oil mix. Quote Link to comment Share on other sites More sharing options...
Bubba Posted May 8, 2011 Report Share Posted May 8, 2011 Tough to diagnose if something/anything is wrong from the vid. Sounds pretty normal for a ring-ding. It would be helpful to check out a few things: Is the sound only when cold/hot? Does the sound change with engine temp/RPM/load? If the noise is most noticable when cold with no load and goes away (mostly) when warm/under load, I'd guess maybe worn wrist pin(s), or possibly some excess carbon buildup in the combustion chamber. From the pics, it looks like it'd be worthwhile to do the repairs, as it's a clean vintage smoker--not many of them left! Quote Link to comment Share on other sites More sharing options...
usafstud Posted May 9, 2011 Author Report Share Posted May 9, 2011 been riding it around the block lately and it seems to be fine.another problem I been having is that sometimes the power just wants to cut out. I need to give it gas to keep it alive for a minute or two and be back to normal. Quote Link to comment Share on other sites More sharing options...
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