cyl bore; 75mm / 2.95 inches
rod stroke; 66.5mm / 2.62 inches
plug gap; .020 ... NGK 8A / Champion K7
Rod play = 0.005 - 0.016 inch
according to my book
So easy way would be to check the stroke measurement.
all 1cyl kohler have 75mm bore
the stroke is what changes and carb size
K335-1 is 2.99 stroke BDC carb ???? 23hp at 5500 rpm
K309-1 is 2.75 stroke HR carb 18.9hp at 5500 rpm
K295-1 is 2.62 stroke , a HR carb, but is 18hp at 5500 rpm
K295-1T is 2.62 stroke , a HR or WR carb , but has more power 20hp at 6000 rpm
so it would be real helpfull if that has the engine cooling cover and info plate
