Bad piston - 200hp

[dtmackey]

Quick question. I have a 1987 220hp Excel that I picked up for very, very short money, it was knows damaged. The engine is is mint condition and was on a trailered boat. I've torn down the engine and found piston #1 has lost the top ring and looks pretty beat up. The head shows a little sign of damage also. I am going to replace the head, but was curious if I can just replace the damaged piston and if needed, can I bore just one cylinder? All the other cylinders have over 130 psi of compression. All cylinders look good, including #1, and show no sign of scoring. I'm guessing that #1 ingested a foreign object. I'm planning on using this in place of my 1987 200hp that runs fine.

Thanks,

David M

[boats.net]

Yes you can bore just 1 cylinder and check the other ones for stuck rings, that sounds like what happened to # 1 piston. After you get it rebuilt, break it in gently with a 50:1 premix in gas and only use 89 Octane or higher gas in a V6 Excell engine.

[dtmackey]

Thanks for the feedback. Upon closer inspection the intake ports were damaged by the rings facilitated the destruction of the piston. While an overbore would have cleaned up the cylinder walls, I was not happy with the port (probably would have been fine). I am sending the block out for a re-sleeve ($155) which will allow me to install a new stock size piston. I also have to replace the wrist pin and con-rod due to the damage from the piston chunks. Should have the block back in about two weeks.