whatrs the difference in 250r cylinders?

[200x_Basket]

some intake ports look like this
http://ebay2.ipixmedia.com/abc/M28/_EBAY_717fa994143c507b30c5a8595b62f751/i-1.JPG
and some looke like this
http://ebay0.ipixmedia.com/abc/M28/_EBAY_1e76d218497b88ccfe21d96dcd876e50/i-2.JPG
another shot
http://ebay0.ipixmedia.com/abc/M28/_EBAY_390fdf806c2fdcbcfa78c1fdb4c1d354/i-2.JPG

whats the difference???

[Mr. Richard]

the one with the webs is a later style. i think it helps to keep from breaking skirts off the piston. it has more support , for the piston lower in the bore,,,,,

[Rocketman]

I thought the one with the webs was the earlier style. 85 86.
and the one with out was the 87 on style.

[dunerash]

The one with the webs is a later style, like Kasey said to help keep piston skirts from breaking, I thought I also heard the "webs" help mix up the air/fuel going into the combustion chamber to get a better burn:)

[markb]

the one with the divided intake is 87-89. i run a 87 on my short rod 86 motor with some sort of lite porting and it runs real good with alot of off idle power. although i have 180 cranking pounds.
mark