The Tohatsu 40 (three cylinder M40D2) not the 2cyl version is also sold as the Mercury Lightning XR in NZ Worksux, with no differences other than, from memory the Tohatsu comes with a temp sensor in the head, otherwise identical and probably one of the most common 40's in the country. They are smooth being a 3cyl.

I love them, having owned 3 over the years plus a Tohatsu M50D2 tiller model, being a detuned 50, they develop some great power for their light weight and are very easy to maintain. Would be a good match to the FC430. Very reliable, although early ones around 2006 did have the odd carb issue. They are the same engines used by Thundercat racers, so can take an absolute hiding and be revved well past what recreational users will ever do. The latest versions have the trim switch on the side and have a few other minor improvements. This model has been in production for over 15 years now.

Pretty sure in tiller form you can't get trim and tilt, but I could be wrong. Yamaha also make a very nice 40 2s, but you pay pretty much the same price as a four stroke for them! I have used both and the Tohatsu / Merc is just as good, perhaps slightly more raucous at WOT.

If you wanted a basic 2cyl, the Suzuki DT40 is great, albeit pricey and noisy, but reliable and goes like stink, but no auto-oiling.

what about the parson motors, they are as cheap as chips, similar to yams, might be worth checking out.

tohatsu 40 no argument best motor ever made for basics and reliability, 3 cyl definitely, yes they do make a 40 horse ptt tiller version, friend bought one a year ago for a flatty.