stevieg909
Recruit
- Joined
- Apr 5, 2010
- Messages
- 1
Hello,
This is my first time posting, so far I'm very impressed by the knowledge in these forums.
I've got a 1987 OMC Cobra I/O drive with a GM four cylinder, either the 2.5 or the 3.0. The casting number is 2770087, and the serial number is M12057RB. There is an 8 inch long crack directly below the manifold, water leaking out. Oil looks good, and the motor runs fine, so I'm assuming it's an external crack only. I've read several threads on identifying the motor, and they all say if it's a 2.5, there will only be a pulley, but if it's the 3.0, there will be a harmonic balancer on the crank as well. In my ignorance, I was hoping someone could take a look at the attached pictures and tell me if I have a pulley or a harmonic balancer (2.5 or 3.0)?
Once I know what size the motor is, I would like to replace the block, but I'm not interested in spending twice what I paid for the boat for a re-manufactured engine. Any advice on where to find a used block? I read that they weren't used very widely outside of marine applications. I'm in Minnesota, called a few places in Minneapolis but no luck. In the mean time it seems my only option is to try and patch it. It looks like someone tried once already with JB Weld, but they didn't get the ratio right cause it's still really pliable, almost like silicone.
Thanks for any help!
This is my first time posting, so far I'm very impressed by the knowledge in these forums.
I've got a 1987 OMC Cobra I/O drive with a GM four cylinder, either the 2.5 or the 3.0. The casting number is 2770087, and the serial number is M12057RB. There is an 8 inch long crack directly below the manifold, water leaking out. Oil looks good, and the motor runs fine, so I'm assuming it's an external crack only. I've read several threads on identifying the motor, and they all say if it's a 2.5, there will only be a pulley, but if it's the 3.0, there will be a harmonic balancer on the crank as well. In my ignorance, I was hoping someone could take a look at the attached pictures and tell me if I have a pulley or a harmonic balancer (2.5 or 3.0)?
Once I know what size the motor is, I would like to replace the block, but I'm not interested in spending twice what I paid for the boat for a re-manufactured engine. Any advice on where to find a used block? I read that they weren't used very widely outside of marine applications. I'm in Minnesota, called a few places in Minneapolis but no luck. In the mean time it seems my only option is to try and patch it. It looks like someone tried once already with JB Weld, but they didn't get the ratio right cause it's still really pliable, almost like silicone.
Thanks for any help!
