I think the 115HP is a V4, but cannot say for sure.
Have a look at a couple of the american forum sites for some detail.
When I get home tonight I'll post a link to a good site thats in my favorites on my PC.
The other place I know off the top of my head is Browns Suzuki. Again an american site, but this dealer has an on-line gallery of microfiche type images for lots of Suzuki engines.
RIBBED For extra pleasure.
Member of the ebay Blue RIB cover club.
Member of the Bombard 380 Aerotec club