twlou Posted July 20, 2011 Author Posted July 20, 2011 hope this helps a few people too:Service Manual for the TW 125http://www.scribd.com/doc/27325375/Yamaha-TW-125-Service-Manual-1999 Quote
Tango Posted July 20, 2011 Posted July 20, 2011 Hey twlou...please keep us posted. I hope that it is just a knackered valve.....but if the valve can move sideways it sounds like the valve guide has been damaged. Sounds like this problem has been brewing for a time when you say the guy who had it before you had to run it on higher octane fuel. Brace yourself though.....it may be a new top-end!!Got fingers crossed for you.Bob Quote
Colin the Bear Posted July 20, 2011 Posted July 20, 2011 We got therehttp://i195.photobucket.com/albums/z28/Colin_the_bear/smiley-gen165.gifFingers crossed Quote
twlou Posted July 23, 2011 Author Posted July 23, 2011 hey everyone, well here's the update. it's costing a fair bit but i want it back on the road....it needs:piston kitrocker armexhaust valvespring seat valvecolletshead gasketLABOUR!! should have the bike back on the road by the end of next week. the guy said that the collets had broken damaging the spring seat and therefore forcing the valve onto the adjustment screw. so overall verdict: exhaust valve knackered = no compression = no vrooooom vroooom Quote
whitedevil Posted July 23, 2011 Posted July 23, 2011 That sucks dude, wouldnt it have been cheaper to get a 2nd hand engine? Quote
oslin06 Posted July 23, 2011 Posted July 23, 2011 Check the earth connection is clean and tight on the frame and battery and the live terminal is clean on the battery if there is no improvement see if you can jump start it with another battery even a car one, that will prove your battery if it is the same then it is something other than the battery or its connections, it sounds like a duff battery to me.Keith Quote
Colin the Bear Posted July 23, 2011 Posted July 23, 2011 Check the earth connection is clean and tight on the frame and battery and the live terminal is clean on the battery if there is no improvement see if you can jump start it with another battery even a car one, that will prove your battery if it is the same then it is something other than the battery or its connections, it sounds like a duff battery to me.Keith Que?http://i195.photobucket.com/albums/z28/Colin_the_bear/matrix-smiley-004.gif Quote
Tango Posted July 23, 2011 Posted July 23, 2011 hey everyone, well here's the update. it's costing a fair bit but i want it back on the road....it needs:piston kitrocker armexhaust valvespring seat valvecolletshead gasketLABOUR!! should have the bike back on the road by the end of next week. the guy said that the collets had broken damaging the spring seat and therefore forcing the valve onto the adjustment screw. so overall verdict: exhaust valve knackered = no compression = no vrooooom vroooom Hmmmm....I think that the problem came from the exhaust valve. I have a bit of a problem with this synopsis of the cause. My normal experience of a failure of a valve spring or collet is a dropped valve. The collet and spring collar are what attaches the spring to the valve. I would think that any damage to these components would cause the tappet gap to open up not close as the valve itself would also not be closing....causing the loss of compression. Now obviously if the valve mushroom has come off and has dropped onto the piston crown then I could see that there would be nothing stopping the valve stem coming up and closing the tappet gap completely.Just my thoughts really.Anyhow, I hope you get the bike back working soon. Bob Quote
twlou Posted July 29, 2011 Author Posted July 29, 2011 hi everyone. just an update to say i've got my bike back and it's running fine. thanks for all the help Quote
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