piston/cylinder help

[razorback746]

i took a micrometer 2 my cylinder 2 day and its way the top of the cylinder is like .8000 off from the bottom its really messed up. i wanna know whats the biggest bore size so i can get the groves out i seen a 1mm over size piston i wanna know if thats big enough to work...

 

[yb200]

you should only need to bore up .010 or .020

 

[razorback746]

ok but do u know the correct mm size of a .10 or .20 cause im gnna have a auto engine rebuild place bore and iv gotta have the right piston

 

[yb200]

take the jub in and they will measure it and look at it and tell you what piston to get....then you have to get the piston so they can bore it to that piston

 

[razorback746]

well they measured it and said my measurements were right but he really doesnt know how much 2 take off 2 were i have i dont buy a small piston so i wanna buy a piston and just bore it 2 that size should i just try a .40 or .50 so i get it right the 1st time

 

[Awk08]

take the jub in and they will measure it and look at it and tell you what piston to get....then you have to get the piston so they can bore it to that piston

/\/\/\/\/\/\ exactly how yb said, and if that shop doesn't know how much to take off, go to a different shop, they dont know they're ass from a cylinder bore!!!

 

[Blaster200boy]

was there a piston that came out the motor on that jug? if so, did it scar the cylinder??? look on the piston for number and letters....mybe you should go to the dealer to get it fitted correctly...then buy a piston (not yamaha) Wiseco works best!!!

 

[razorback746]

yea its a standard piston and the rings were froze inside the gap were the rings go but i juat wanna know the exact bore

 

[fioz600r]

a standard Blaster piston stock bore is 66mm.

 

[super noober]

i took a micrometer 2 my cylinder 2 day and its way the top of the cylinder is like .8000 off from the bottom its really messed up. i wanna know whats the biggest bore size so i can get the groves out i seen a 1mm over size piston i wanna know if thats big enough to work...

dont all cylinders have a tiny taper to them?? am i dead ass wrong?? lol :-/

 

[sr5bidder]

66.25 mm would be a .010 over
66.50 mm would be a .020 over
66.75 mm would be a .030 over

and so on...just take it to some one who does know that you have to have the new piston in hand in order to come up with a final bore measurement

 

[sr5bidder]

dont all cylinders have a tiny taper to them?? am i dead ass wrong?? lol :-/

cylinders should not be tapered, it is the piston that is actually bigger at the skirt and smaller by the rings

 

[super noober]

cylinders should not be tapered, it is the piston that is actually bigger at the skirt and smaller by the rings

ahhhhh thats what it was... thats why i said i coudl be wrong

 

[razorback746]

ok thanks guys lots of help im gonna go ahead and get the 1mm over size bore so i get it right the 1st time and i have good compression. but is there anything i should watch out on the bottom end cause i gotta put in a new crank any do's and don'ts

 

[fioz600r]

ok thanks guys lots of help im gonna go ahead and get the 1mm over size bore so i get it right the 1st time and i have good compression. but is there anything i should watch out on the bottom end cause i gotta put in a new crank any do's and don'ts

You should bore it as small as you can bro. You dont want too take life out of your motor. Going 1mm you are loosing half off the cylinder bores. If you can go .25mm over or .50mm over than I would do that.

 

[sr5bidder]

unless the scratchs are really bad and total 1mm deep ( wich I doubt)
Do what ^^^^ he^^^ says or your giving up 3 life cycles ....
compare it to taking 4 lifes away from a cat the first time he has a close call

 

[brandoz28]

man just take it to a reputable shop (not where you just took it) and have them bore it and tell you how big of a piston you need to get.