Good morning everyone,
I have a late model atomic 4 that I recently got running after is sat for a while. From what I understand it was rebuilt in the early 2000's and meticulously cared for by that owner. Then the boat was sold to someone that wanted a diesel so they pulled the motor. I suspect the set it on a pallet at the boat yard and covered it with a tarp and left it there until I picked it up. After some troubleshooting with the cooling system I got it running well with no water intrusion. When the boat is not in gear the motor will rev up as it is supposed to and behaves normally. However when in gear it will not exceed 1500 rpm. It reaches 1500 at about half throttle and stays at 1500 all the way to full throttle. I did a pressure test and got the following results:
1- 0psi
2- 65psi
3- 65psi
4- 75psi
My immediate assumption is that I need to rebuild the engine. I'm going to pull off the head and check to make sure I have no stuck valves or carbon buildup that's preventing them from sealing properly. So my question is, is there anything else I should look at before continuing with a rebuild? I have already pressure tested the water jacket in the block and manifold (and installed a new manifold because that was the root of my previous problem) and everything there checks out. As I am relatively new to this world of atomic 4's I just don't know if I'm missing something obvious that could solve my problem, but in what knowledge I do have of similar engines, I suspect worn piston rings possibly from sitting on the pallet in the boat yard for who knows how long. Any help or advice would be appreciated!
I have a late model atomic 4 that I recently got running after is sat for a while. From what I understand it was rebuilt in the early 2000's and meticulously cared for by that owner. Then the boat was sold to someone that wanted a diesel so they pulled the motor. I suspect the set it on a pallet at the boat yard and covered it with a tarp and left it there until I picked it up. After some troubleshooting with the cooling system I got it running well with no water intrusion. When the boat is not in gear the motor will rev up as it is supposed to and behaves normally. However when in gear it will not exceed 1500 rpm. It reaches 1500 at about half throttle and stays at 1500 all the way to full throttle. I did a pressure test and got the following results:
1- 0psi
2- 65psi
3- 65psi
4- 75psi
My immediate assumption is that I need to rebuild the engine. I'm going to pull off the head and check to make sure I have no stuck valves or carbon buildup that's preventing them from sealing properly. So my question is, is there anything else I should look at before continuing with a rebuild? I have already pressure tested the water jacket in the block and manifold (and installed a new manifold because that was the root of my previous problem) and everything there checks out. As I am relatively new to this world of atomic 4's I just don't know if I'm missing something obvious that could solve my problem, but in what knowledge I do have of similar engines, I suspect worn piston rings possibly from sitting on the pallet in the boat yard for who knows how long. Any help or advice would be appreciated!
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