GS1000G barrels

[marco]

Hi I need help, I've just started a top end rebuild on my GS as it was running a bit rough and had a couple of minor oil leaks.
What I found was a horror story, number 3 barrel has two massive grooves in it, the piston was missing one circlip and the other circlip was 2mm diameter too small and ready to fall out.
the gudgeon pin/ wrist pin was scraping against the side of the barrel. I've measured my barrels and they are 73mm inside diameter, the pistons are marked with the numbers 350. am I right in thinking that this has been over bored a lot in the past.
Am I going to have to get new barrels, pistons and rings?

IMG_20240628_101342334.jpg

[marco]

IMG_20240628_102733700.jpg for some reason I can only upload 1 attachment at a time

[unfocused]

Yes, stock is 70mm and your bore is 3.5mm over - or 1100cc.

You can sleeve the jugs or replace.

Whatever you do, expect to bore the new jugs to the same 3.5mm over-bore. I've memory serves me correctly, 1mm and 3.5mm are the only available pistons.

Cruizin Image has listings on Ebay - I haven't used his pistons but I will be soon.

[marco]

thanks for that, I may have found a set locally ready bored to 73mm. as long as it's not a bloody scammer

[Nessism]

The 1100G is 73mm. And yes, there are 73.5mm over bore pistons available (both Wiesco and Cruzin Image). The 1000 liner gets really thin at 73.5mm, but it's doable. Or source a new cylinder, as you are chasing.