Another issue to complicate matters is bore size. I noticed on the Mikes Carbs chart that the 261 takes a significantly bigger Jet. So, must be that a larger cylinder takes more fuel. With a .080 overbore (246 cu in.) maybe this is why the listed Jet is way too small.
The difference is between .056 (235) and .065 (261).
The 261 takes a significantly larger jet, because the carburetor used on the 261 is a significantly larger carburetor than the one used on the 235.
Jon.
