Yamaha says 126-143. 17 lb. difference between them shouldn't be a deal killer. That's a small cooler.
Consider a Tohatsu/Merc/Evinrude or a Suzuki 20hp if your worried about weight. Both are in the 100# mark for pull start models, and would be about 120lbs with tilt, trim and electric start. The F25 is the lightest 25hp though as it's a big 2cyl vs an inline 3cyl as used in the other brands
Also consider the Suzuki DF30A as it's lighter than a Tohatsu as well as being cheaper.
http://www.suzukimarine.com/~/media/Marine/Brochures/14DF25A30APIB.pdf
Yeah. you gain 10 lbs for an extra cylinder. From what I see the F25 idles rather lumpy due to being a twin cylinder, but Yamaha has the troll control if you needed it..
weird it's not available as that brochure came from the US site and it's listed. But your right I can only find US reference to it in a long shaft
I like that Suzuki weight though, 159 lbs for the 30HP with remote and PTT. Now I'm considering this in the long shaft and getting a transom extension: http://www.koskiboatworks.com/custom-whaler-accessories.html, he says it weighs 5 lbs has put 50HP with PTT on them...