yar leave this Japanese thingy for good,, u wont find it,,even if u do,, u wont be sure if they really are japs,,
for cylinder buy a new cylinder,,
rest piston ring bearing etc are available locally ,,
just make sure u buy original Yamaha parts,,
and most importantly rebuild seems as just replacement of faulty parts and washing with petrol but its a science within itself,, it involves checking for tolerances,, warping of various surfaces,, which none of our mechanics do,, i had rebuild my friends 2007 honda cd 70 , it costed 6000 rs,, believe me in the entire process the mechanic not even used the ruler/scale let alone the use of calliper,dual gauge,micrometer,surface level check,,
a good rebuild with the cheapest Chinese parts will out last a poor rebuilt with aircraft quality parts.. take these words..
our mechanics just replace the bearings they don't check the surface where bearings go for play...
same thing with the crank balancing .. they just just a metal hammer to balance it .. and there balance in my opinion is just 70 % balance.. which results in seizure of engine.. had they use a proper balancing tools the rebuild would last as genuine engine..
they don't check for warpage .. surfaces may become curved and they need to be levelled for proper fit and hence smooth running of components .. crank case face where cylinder fits should be checked for warpage.. similarly the head face ..
hope u choose a good mechanic this time.. who uses the tools ..