Questions on top end rebuild

[Ayeitsnico]

My top speed is only 44 and compression was 112 cold a few months ago.

1) I dont know what the cylinder is bored to so how do i find out so i know which size to get?

2)Do i need the entire top end kit or just rings?

3)Do you always need to hone your cylinder or is it ok not too?

4)What is a good video to help me with installation?

 

[tuffluckbmx]

you can probably find the piston size on the top of the piston.

you have to dig in and see if theres any prior issues before you know what you "need"

I bought a new cylinder but I definitely could have reused mine with no work. like I said,just depends on what you see when you get inside.

I found this extremely helpful.

 

[Slydog]

My top speed is only 44 and compression was 112 cold a few months ago.

1) I dont know what the cylinder is bored to so how do i find out so i know which size to get?

2)Do i need the entire top end kit or just rings?

3)Do you always need to hone your cylinder or is it ok not too?

4)What is a good video to help me with installation?

First off what is your compression right now.? If 100 it's time.
1 to find out what size your bore size is now
You would have to remove cylinder head and might have to clean top of piston off allitte
There will be the piston size etched in piston top.
There will be two rows of numbers
On top. The ones you want should be. Towards the rear( towards carb)
66.00 mm stock
66.25 mm
66.50 mm
66.75 mm
67.00 mm
And so no up to 68 which is max bore
Your cylinder will ned to be bored to next size up as cylinder wears and piston to cylinder wall clearance gets to big

 

[Slydog]

Or at size you have Bring it to a machine shop they will measure cylinder and tell you what size you have and what it needs to be bored to. They can also order you piston and gaskets for you . that way everything is correct