I am new to the forum, so I would like to say hi to all and thanks in advance for any help. I have a 225 4-Stroke with a bad piston. I have done some work on outboard motors before, but not this one. Just wanted to know if there are any tips or shortcuts out there that anyone could give me before I dig into this thing. It only has 194 hours on it so hopefully it is only the rings on the #5 piston with no damage to the cylinder, but wont know until I get into it. I have done a compression test on it and it only shows one low cylinder. It looks like I will be able to get into it without removing the flywheel........any help??? Thanks!
Thanks rodbolt. It looked like I might be able to remove the botom of the motor and get to the pistons without having to remove the entire powerhead. Any special tools I will need? Tips to tell if it is the head gasket or piston rings without tearing into the entire thing? Compression is good in 5 of 6 cylinders and the motor is blolwing white smoke if I take it above idle like oil is getting into the cylinder. There is not pinging sound, actually sounds like it is running perfect, the only way I knew there was a problem is because I started loosing power while I was crusing on plane. When I did the compression test I assumed that is is like a car motor and more then one piston would loose compression if it was the head gasket? Would that hold true for an outboard?
Well, I tore it apart today and might have gotten lucky. Looks like it might be a head gasket. There is something weird going on with the cylinder head though. On the bottom cylinder, the one that had low compression, there is some erossion. I have never seen this before. The motor has only over heated a handfull of times, and whas shut down immediatly every time to clean the soot out of the intake. The piston and cylinder are still in perfect shape, the piston head couldn't have been hitting it. Take a look and see if you can tell what might have caused it. I would like to know so I can possibly fix another problem. I am having the erossion built back up and machined out before I replace the gasket. Thoughts???
Thanks for the help Larry. T Stats are good. Just replaced water pump 30 hrs ago. I didn't buy it new, but as long as I've owned it the "pee" tube has never been as powerful as other 225s I see. Could that be the problem causing over heating? How do I fix? By the way does anyone have a torque chart for when I do get to put it back together?