266se cylinder

[Craigb]

Can I swap a 266 cylinder and piston for a 268 combo? I know the covers are different but everything after the cylinder will be off the 266 saw. Do I need a 268 intake block though? The only reason I’m doing this is availability, I can get a meteor 268 but not a 266.

[adw]

Yes you will need to change the induction block, gaskets and screws, can’t think of any other reason it will not fit.

[Craigb]

I’m a little confused. The first cylinder is 50mm bore with a solid piston whereas the third is 50mm with a piston that has windows. Why the difference?

[spudulike]

You typically have windowed pistons to allow a better flow of fuel/air vapour in to the transfers. Solid walled pistons typically have cylinders where the lower transfers are in the base of the cylinder and not in the cylinder wall - like the MS660 or 395xp etc.

I say "typically" as there are exceptions from the likes of Makita/Dolmar..

If you look at the piston, you can see the sidewalls are angled to allow increased flow in to the transfers, no idea why they produced two kits like this but it looks like they are covering two separate OEM parts.

I have done a few 268XPs and all have had windowed pistons so I would go with the same.

[adw]

One for the 266, and one for the 61 with open transfers.

[Craigb]

So if I were to port it the windowed would be the better option as it increases flow.

[spudulike]

Very difficult to tell without seeing if the transfers are open on the cylinder with the piston with no windows but the windowed version looks more like the original part  and would be my choice. 

[Craigb]

Both cylinders have transfers in the walls as oppose to the base by the look of them.

[spudulike]

Your choice then but as I said earlier, a windowed piston will have better flow characteristics.

[adw]

So, the 266 had a closed transfer port cylinder, and a windowed piston, the 61 had an open transfer port cylinder and a non windowed piston, you could fit the windowed piston in both 266 and 61, however you cannot fit a non windowed piston into a 266.

So I have no idea what these different cylinders and pistons are about.