I'm looking for the specs on the Mercury Racing offshore engine mounts that come installed on the 525. How far must the stringers be spaced (minimum) to install the 525 engine? I tried to find an installation .pdf on the Mercury Racing website but no luck.

All the engines use the same dim. or at least pretty close .

Unless u built a boat and need to know . But if u have one they should fit.

My stringers are spaced 21" so that the stock Mercury mounts bolt to the top of the stringers. I'm moving my stringers out to 26" (inside spacing) and I just want to be sure that is wide enough to accomidate the offshore mount, specifically the one that comes on the 2008 model 525, 600, 662, 700....

It has been a while but i am pretty sure the industry standard is 28 inches inside to inside.

I went straight to the source today and the answer is the motor mount bracket is 32.88 inches wide. Does anyone have a 525 single that is mounted on stringers that are closer together, like 26"?

Most are mounted on "L" brackets and there are adjustable holes. YOu should be OK. Make sure that the brackets are at least 3/8" thick to avoid bending.