Whats the stock bore for 2003 yamaha blaster?

rustler2580

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Oct 17, 2011
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new york
I am finally getting a piston for my blaster but i need to know what the standard bore is so i get the right piston, It does not need to be bored because the cylinder is fine. So please some one let me know. Thanks
 
66.00mm is stock bore period. 66.25mm would be .10 over bud.


edit: the jug on my blaster was just mic'd and read 66.xx. honed it and it still got a 66.00mm piston put back in it.
 
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ok thanks JON S, Thats why i wanted to ask on here because wasnt sure of the stock/standard bore for the blaster, and by the way man your black blaster looks just like mine except my frame and sh*t aint painted yet, going monster energy
 
ok thanks JON S, Thats why i wanted to ask on here because wasnt sure of the stock/standard bore for the blaster, and by the way man your black blaster looks just like mine except my frame and sh*t aint painted yet, going monster energy

i hear ya man. mine is the stock all black SE lol no paint needed. B)
 
Thats werid. I swear it was 66.25. Guess im wrong thanks for correcting me!

yeah, not trying to bust balls or anything. that lil bit of misinformation could have cost the man money he didn't need to spend though. that is if he would have taken it to heart.
 
Nice bro, What kind of piston should i go with? Im trying to find a decent stock piston kit with the rings, and gaskets and sh*t on ebay for a decent price.
 
WIESCO all the way man. Forged > cast any day of the week. less trouble later on too.
 
yeah, not trying to bust balls or anything. that lil bit of misinformation could have cost the man money he didn't need to spend though. that is if he would have taken it to heart.

Yeah i know what your saying. Sorry bro. Your right i just looked up stock rebuild kits its 66.00
 
So a WEISCO piston right? Just trying to find a kit with a decent price on ebay because my mom is buying the parts for me, after i fix it i might hang on to it i dont know though, might sell it or trade it because i want something else, like 300ex or warrior something down them lines
 
So a WEISCO piston right? Just trying to find a kit with a decent price on ebay because my mom is buying the parts for me, after i fix it i might hang on to it i dont know though, might sell it or trade it because i want something else, like 300ex or warrior something down them lines


go with a Wiseco piston w/ rings and bearing. OEM gaskets are the best or Cometic EST as well.
 
So a WEISCO piston right? Just trying to find a kit with a decent price on ebay because my mom is buying the parts for me, after i fix it i might hang on to it i dont know though, might sell it or trade it because i want something else, like 300ex or warrior something down them lines

Weisco is one of the higher priced kits but trust me they are well worth it!!! Great pistons,Also a piston kit is something you do NOT want to cheap out on! And if you are looking for a four stroke sport I would go bigger than the 300ex, Your blaster is faster than a stock 300ex or pretty dam close! Id go with a 400ex or Z400. OF course i am telling you to go with the z400! But IF you are looking to upgrade from the blaster the z400 is amazing!
 
found weisco piston kit on ebay, comes with piston, rings, piston pin and set of c clips for lil over 72 bucks, and ya my cousin had a blaster and swapped his plus 500 cash for a z400
 
You will still half to take that piston in with you and have it board to match the specs and expansion of that particular piston.This maybe why his boar was .10 over.This is just one of them things you want to do right the first time.Check your side to side clearance with a fealer gage on the bottom end of your canecting rod.Replace upper bearing.You may not need to rebore but still half to hone it out and correctly match the pison and its design specs to your bore.You will not have a correct brake in if you just throw a piston in it.Best to have the pros match it for you.Half to take the head in dont cost that much.
You may be able to get by with stock piston but still half to hone it.Not something I would do.I would go ahead and go with the next bore size.
 
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66.00 is the stock size or bore of the piston and its 66.25 is the bore of the sleeve the sleeve has 2 be bigger because the rings ad a few mm