61x cylinder how do you check bore?

[coolmann7]

The guy i bought my motor from said its bored over one size and i need to buy pistons. I have the right stuff to check it how many MM's should it measure? What is stock, 1 over 2 over etc? or direct me to the thread i need. thx

 

[eel]

81MM is stock.

Depending on the piston brand, they usually go up in 0.25mm increments until 83mm then jump to 84.

Also, if you carefully clean the piston crown, the oversize amount is usually stamped there. ie: .25

 

[coolmann7]

yeah the sad thing is i don't have any of the pistons.... they threw them away

 

[Mouthfulloflake]

measure the bore in differetn locations, up and down the cylinder, and front to back and side to side.

check for cylinder taper, check the measurements against max callouts.

if its out of spec, order the next size piston up that will true it all up, and take pistons, and cylinder to a machinest, and have it cut to fit the new over sized pistons.

 

[coolmann7]

thanks.... that helps