A cordless skil saw or jig saw would be my choice.
I can't imagine either of those engines having enough power to drive a 250mm saw blade. It usually takes a 2hp electric motor to drive one, for petrol power you usually need to double the HP to get the equivalent output so you will need at least a 4hp engine. You also have to think about blade speed as there will be an optimum speed for your blade and gearing your engine up with pulleys to suit will reduce its power too.
If you have a chainsaw one of these works very well.
https://www.amazon.co.uk/RocwooD-Ho...hvlocphy=2826&hvtargid=pla-700786064595&psc=1
I would buy it locally though as the chainsaw pivot can be shoddy & allow the saw chain to foul the guard. My BIL bought one & I had to re engineer the pivot to make it safer.
I can't imagine either of those engines having enough power to drive a 250mm saw blade. It usually takes a 2hp electric motor to drive one, for petrol power you usually need to double the HP to get the equivalent output so you will need at least a 4hp engine. You also have to think about blade speed as there will be an optimum speed for your blade and gearing your engine up with pulleys to suit will reduce its power too.
If you have a chainsaw one of these works very well.
https://www.amazon.co.uk/RocwooD-Ho...hvlocphy=2826&hvtargid=pla-700786064595&psc=1
I would buy it locally though as the chainsaw pivot can be shoddy & allow the saw chain to foul the guard. My BIL bought one & I had to re engineer the pivot to make it safer.