Help and advice on this cylinder please.

[speedy]

Advice please folks. I started work on my jet 200 project recently,which surposedly had a factory 4 200 top end,with an Asso piston on the Spanish engine. I bought it as a non runner.As I haven't got another barrel to compare it against and the fact I've never run a factory 4 on any of my scoots,I have nothing to compare it to or next to. Now the piston in the scoot,turned out to be a three ring Asso,with the big thick crap rings and was hardly used. However it is 67mm and not 66mm,so 205 then? The bore has in recent times been honed as the marks are still clear,yet so are the ring marks at the top of the cylinder. When I got the vernier on the cylinder,it was showing a bore size of 67.4 mm,which explained the looseness of the piston in the bore. So now I was looking at having to convert to 225,70mm,but another problem arose. Looking at thew transfers,they are relatively large as I can get my index finger in ,right to the top and move it around and I don't have the thinnest of fingers to be honest. Now I'm not sure if these cylinders are like this as standard,or whether this has been ported.[ The inlet and exhaust are nice and smooth/polished,but again,i'm unsure if this is as you would usually find on an Indian cylinder? ] Why I ask about the transfers and a possible problem is that,if it were to be bored to 70mm,the walls would collapse.as there isn't enough meat on the cylinder wall to bore to that diameter. Is it possible that this is an old 205 Honda conversion,bodged together with a crap piston as it's ran out of oversizes,and were these conversions ported out towards the cylinder wall,or am I barking up the wrong lamppost?cheers,Speedy.

[rosscla]

You need to take some more measurements.

What's the distance between the gasket faces?
From top of barrel to top of exhaust?
From top of barrel to top of transfers?
From top of barrel to bottom of inlet?
Height of piston?

I think it unlikely to be a honda as I think the piston has a different pin position and asso are usually standard.

First guess would be it's been rebored a few times.

[fastfrog]

post a pic and we'll see more clearely if it's been ported or not....