RD 125 LC Mk2 (none ypvs)

[sheffieldlad]

Hi all,

My first post here.

I have a mk2 1986 LC 125 and I think the piston rings have nipped slightly as It has lost some compression.
I'm planning on either buying a new piston/rings if the barrel looks ok or I will have the barrel bored to the next size and replace piston/rings accordingly.

I know some 80's jap bikes have some sort of 'friction less liner' which was plated into the barrel and can only be bored out so far.
Can anyone tell me how many sizes I can increase the barrel by before I have to have the liner re plated or replace the barrel?

I'm only asking because the previous owner seized the piston and the bike has had a rebore already to the next size up from standard.

The bike is a 1986 C reg RD 125 LC Mk2.

I'm not 100% certain that the piston rings did seize and I plan to get a compression tester before I strip the head off.

Many thanks for any help

[raven13]

you can go safely to +2mm after that its possible but its a bit short on meat.

[sheffieldlad]

Jun 15, 2013 16:42:38 GMT 1 raven13 said:

you can go safely to +2mm after that its possible but its a bit short on meat.

Many thanks.

Is it possible for me to measure the bore with a set of vernier calipers and compare it to the original size?

If so, would you happen to know the original size?
I don't have a manual for the bike yet.

Thanks again.

[raven13]

56mm standard bore

[sheffieldlad]

Jun 15, 2013 23:24:20 GMT 1 raven13 said:

56mm standard bore

Many thanks