Hello again,

I have one crazy question;
Will a 660XTZ camshaft fit in and function in the 3AJ engine..?
Its a very wild thought for a modification, I know!

Even it seems impossible, you never know with yamaha.
The 660 has one more valve but one cam presses two of them.
I´m very interested in the automatic decompression mechanism, it would make those winter startings easier and save lot of watts from battery + eliminate the need for the decomp cable when kicking.

Anyone have an idea?

Matt

Don't even think about it!

They're completely different. It's not just the number of cam lobes, you also need to consider the lobe shape & journal diameter.