Not off the top of my head, but if you clicky this http://www.ishopmarine.com/ishop/store/yamaha/
and once loaded click on the "outboards" link in the "parts lists" section. Drill down to your engine.
Now the boring bit. Once you have found yours, open another browser window & get the two engines side by side. All you can do is go through the entire parts list (and I mean the whole thing - it may be as simple as a carb change, it may be a wole lot of parts working together to keep the horses at bay.
One thing to be aware of is that the 9 may have different stuff on the transmission (e.g. gear ratios, bearings etc), so you really must go through the whole lot to be sure.
I forget when, but therre was a thread a while ago where Locozodiac showed that apart from the block, not a lot else was similar. The cost of the spares to upgrade was similar to trading it in for the bigger engine! My memory says it was a Tohatsu, but have a search - there's plenty of threads on this subject!