Outboard Help
 

I have to replace pistons in a 25hp Tohatsu. I know it has had some modifications to it, but I do not know if the cylinders have been messed with....I am ordering the pistons and doing it myself. This may be a dumb question, but is there anyway to measure the cylinder to see what size pistons I need? I wasn't sure how they sized pistons. Thanks in advance for any input guys, I appreciate it.

If you have a service manual it should give you these specs. Nothing else, call a dealer and they can look it up. You'll have to use a micrometer to check diameter and roundness.

Sent from my SAMSUNG-SGH-I727 using Tapatalk 2

You need to find someone with an ID micrometer to measure them. Google the model number and you may be able to find it online. If you don't know a machinist run it by a mom and pop machine shop and they'll measure them for you. When I worked at a machine shop back in the day I did it a couple times for people. Bring them a cold 6 pack