May 15, 200818 yr Just pick up Ty80 Runs well , However it has a funny noise in low revs. Sound like the piston is hitting spark plug tapping (only slytley) . Taken head off and all look clean no damage that l can see. I've put some rubber in the head finns and it has dulled the sound a bit but it's still thier.... lots of compresstion & it's quick....... Could it be little end? Any idea's Many thanks Martin
May 16, 200818 yr Sounds like the big end... take the head off and turn the engine over so the piston is moving down, then press the top of the piston firmly and see if it clicks down a little bit, i bet it does, if your not sure take the barrel off and check it. Scrumpy
June 6, 200818 yr Just pick up Ty80 Runs well , However it has a funny noise in low revs. Sound like the piston is hitting spark plug tapping (only slytley) .Taken head off and all look clean no damage that l can see. I've put some rubber in the head finns and it has dulled the sound a bit but it's still thier.... lots of compresstion & it's quick....... Could it be little end? Any idea's Many thanks Martin
June 6, 200818 yr Just pick up Ty80 Runs well , However it has a funny noise in low revs. Sound like the piston is hitting spark plug tapping (only slytley) . Taken head off and all look clean no damage that l can see. I've put some rubber in the head finns and it has dulled the sound a bit but it's still thier.... lots of compresstion & it's quick....... Could it be little end? Any idea's Many thanks Martin Would be interested in what you find - I have a similar symptom, mine fades and sometimes goes away when the bike is leaned over. Regards : Martin
June 6, 200818 yr TY80- could be many things, piston slap, loose small end bearing etc. second poster: tilting to one side. I have a gasGas200 that has really bad sounding rattle. Checked top end. all fine, but changed piston, rings, pin & bearings anyway. $200+, and same noise. Then noticed it changes tilted to one side and not the other. Ended up that the crank is moving side to side in the main bearings. When on compression, the crank is pushed one side by the helical teeth of the drive gear to transmission. Then, after TDC on power stroke the loads reverse and it moves to the other direction on the helical. Helical tooth sort of acts as a spiral thread and the crank walks back and forth. In this case. .014 inch. Pulled apart, used high temp red loctite to glue the right (drive) side bearing to shaft. Solved it.....for about a month. the noise returned. The next task will be to measure clearnace again and shim the crankshaft. Grainger has some 25 mm ID shims of varying thickness that I think will work. Apparently it doesn't hurt the engine as it has ran for a couple years and not anyworse. Just embarassing and sounds like a piece of junk. I want to fix it right. So not sure if applies to TY80 but it might. I have had 3 TY80 but haven't worked on them an at least 8 years. kcj
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