I have a sig senior on floats set up with 3 channel that i got used I put a thunder tiger 46 off land but didn't know if i should put a 60 + engine on it or for the water i have a 65 os la ,and a 61 magnum

I've gpt an OS .90 four stroke in my Kadet senior and it's not too much. Flies good. The bigger engine you've got might be ok.

Good luck

HughO

Here's a couple of pics at the pond.

I have seen Seniors fly from water with .40s all the way up to .91Four-strokes. A TT46 is a good motor and you should be able to fly just fine with it.
It is a myth that floatplanes need gobs more power. Full-size piper cubs carried floats around with only 65 hp. This one has a .45 and it would hover.

I don't remeber what the white one with the red stripes had for power.

If yours seems to be underpowered, you probably have those awful, heavy, oversize, built-up plywood floats. Get some nice light foam-core floats and go have fun.

Of the choice of your three engines The no brainer choice for me would be the .65 LA. It is an ideal engine Size/user friendliness in a two stroke for a Senior on wheels or water. I have flown many Seniors on and off the water my own and for others and that LA65 is a great engine for a senior.

John

I have a 70 4-stroke on mine, and in my opinion, the perfect match. I'm using my 42" slim foam core floats without a water rudder.
Seaplane

Have had both a 4 stroke .56 and a 4 stroke .72 in mine. To me the .56 is a little more realistic power. The .72 was effortless.