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  1. #1

    Default Rust on spark plugs

    Hi Chrysler 318 Colleagues,

    I bought a 1972 Uniflite Sport Fisherman cuddy and I pulled all the sparked plugs and I saw significant oxidation on one the electrodes. I believe this was the first spark plug close to the starter so you can get a sense of the location. Does this mean I should expect a cracked manifold? I know the manifolds are not in the greatest shape. It has been so difficult finding someone who is willing to work on an old engine. I am even working with auto guys now because I gave up on the marine mechanics. I am more concerned about the health of the 1970 block, that the previous owner said he put in 5 years ago. If I change the manifolds and risers, I do not know if I can see if the block is working if it had water inside. I am not a mechanic so what would you guys do in this situation. Compression tests, cylinder tests? I want to know how deep in my pocket I need to go. Thanks in advance,
    Robert

  2. #2
    Join Date
    Mar 2008
    Location
    Bruford SC , U.S.A.
    Posts
    358

    Default Re: Rust on spark plugs

    My guess is no one wants to spend time and your money digging around. If you think the manifolds have seen better days start there but
    if your concerned about 1 cylinder you should be able to get in there enough to put a compression gauge beforehand to check the motor

    If your not mechanically inclined and you bought a 50 yr old boat, your soon going to be....

    jack

  3. #3
    Join Date
    Dec 2014
    Location
    Ontario Canada
    Posts
    99

    Default Re: Rust on spark plugs

    Quote Originally Posted by RobertSLP View Post
    Hi Chrysler 318 Colleagues,

    I bought a 1972 Uniflite Sport Fisherman cuddy and I pulled all the sparked plugs and I saw significant oxidation on one the electrodes. I believe this was the first spark plug close to the starter so you can get a sense of the location. Does this mean I should expect a cracked manifold? I know the manifolds are not in the greatest shape. It has been so difficult finding someone who is willing to work on an old engine. I am even working with auto guys now because I gave up on the marine mechanics. I am more concerned about the health of the 1970 block, that the previous owner said he put in 5 years ago. If I change the manifolds and risers, I do not know if I can see if the block is working if it had water inside. I am not a mechanic so what would you guys do in this situation. Compression tests, cylinder tests? I want to know how deep in my pocket I need to go. Thanks in advance,
    Robert
    Hi Robert
    I also have a 1972 sport sedan with twin 318 engines.
    Rust on a spark plug could simply be the result of the boat being stored in a windy location over the winter and the intake or exhaust valve stopped in the open position. Before you go spending a lot of money, just clean up the plugs and test the engines. The 318 with marine manifolds in place can be difficult to get a compression gage in place to test them. Another source of general engine knowledge in your area might be the old car club in your town. Let us know how you make out.

  4. #4

    Default Re: Rust on spark plugs

    Quote Originally Posted by 300hb View Post
    My guess is no one wants to spend time and your money digging around. If you think the manifolds have seen better days start there but
    if your concerned about 1 cylinder you should be able to get in there enough to put a compression gauge beforehand to check the motor

    If your not mechanically inclined and you bought a 50 yr old boat, your soon going to be....

    jack
    Thanks so much, Jack. Sage advice for sure and much appreciated. I need a new starter. I am unsure about engine rotation. Big problem for a green horn as you well know. I stand by the transom and the belts move CCW. I just want to buy a new starter for the new mechanic. LM318 1970. Standard Rotation Engine. Can that be CW or CCW? I am not sure. I did not realize Chrysler would manufacture engines so differently. This is a 1970 engine labeled on the block. Like a new boater, I bought a CW starter and the belts move CCW. Can you tell me if I need to correct anything. The flywheel does not create any spark. In fact, the carb spits gas. I am a new boater with no original manual so please let me know if I should be buying a CCW starter to engage the flywheel correctly. Forgive my ignorance. Thanks again in advance, Jack. The marine mechanics in NY are POS (plural). You pay them what they ask and they do not come back.

    Robert (Brooklyn, NY)

  5. #5
    Join Date
    Dec 2014
    Location
    Ontario Canada
    Posts
    99

    Default Re: Rust on spark plugs

    This picture shows what Arco believes to be the correct starter rotation. Good luck.
    Click image for larger version. 

Name:	Starter Rotation 1a.jpg 
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ID:	27331
    I'm going to the boat this afternoon. I'll see if I can get a part number.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Starter Rotation 1.jpg 
Views:	8 
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    Last edited by Toonl; 07-10-2021 at 01:53 PM.

  6. #6
    Join Date
    Dec 2014
    Location
    Ontario Canada
    Posts
    99

    Default Re: Rust on spark plugs

    Hi RobertSLP
    The first item we need to address is that most all motor rotations are described by viewing the engine or motor from the drive end of the motor. On a LM318 this will be from the flywheel end of the motor looking towards the water pump at the other end of the motor. So if you are at the transom and the motor water pump is closest to you the CCW rotation of the belts is actually a CW engine when viewed from the other flywheel end of the motor. On my boat the water pumps are closest to the transom. If yours is the same a CW starter is the correct one for the starboard engine.
    I checked my starters and the port engine (left side looking forward inside the boat) starter is a 2095509 and the starboard engine ( Right side looking forwards inside the boat) starter is a 1889297. These are Autolite part numbers.
    With a starter the direction of rotation will be determined looking at the drive end of the starter.

  7. #7
    Join Date
    Nov 2005
    Location
    Chi West, IL, USA
    Posts
    889

    Default Re: Rust on spark plugs

    Quote Originally Posted by RobertSLP View Post
    ........... I am a new boater with no original manual so please let me know if I should be buying a CCW starter to engage the flywheel correctly. Forgive my ignorance.......
    Robert (Brooklyn, NY)
    Although not the original a lot of relevance and the price is right. Click the green "DOWNLAOD" link, check the "Not A Robot" box, and then the "Get Manual" link.........
    CHRYSLER LM 318 SERVICE MANUAL Pdf Download | ManualsLib

  8. #8

    Default Re: Rust on spark plugs

    I bought a 1972 uniflite sport sedan last summer. On my way home it overheated. I have twin 318's like you. Plugs had rust on them. I replaced the plugs, put on new wires.
    I replaced the manifolds thinking they were bad and still overheated.
    I took the heat exchangers to a rad shop and had them cleaned. still over heated.
    replaced impellers on raw water pumps, still overheated.
    I replace both fresh water pumps. both were auto pumps, so the overheating engine was spinning the wrong direction. So the marine one should have fixed the problem. Still overheated
    I then took all of the risers in to a rad shop to get cleaned. I am now running fine!

    Tips for you. Replace your plugs. Replace the impellers on both of your raw water pumps (they are probably sherwood G7B's)
    Run the engines.
    after you get up to 160F, feel the top of your risers. They should feel hot. Now feel the bottoms. They should be cold. That means that your cooling system is working fine. Otherwise you need to troubleshoot.

    But id definitely just start changing the plugs and seeing how things run.

    Good luck!
    Quote Originally Posted by RobertSLP View Post
    Hi Chrysler 318 Colleagues,

    I bought a 1972 Uniflite Sport Fisherman cuddy and I pulled all the sparked plugs and I saw significant oxidation on one the electrodes. I believe this was the first spark plug close to the starter so you can get a sense of the location. Does this mean I should expect a cracked manifold? I know the manifolds are not in the greatest shape. It has been so difficult finding someone who is willing to work on an old engine. I am even working with auto guys now because I gave up on the marine mechanics. I am more concerned about the health of the 1970 block, that the previous owner said he put in 5 years ago. If I change the manifolds and risers, I do not know if I can see if the block is working if it had water inside. I am not a mechanic so what would you guys do in this situation. Compression tests, cylinder tests? I want to know how deep in my pocket I need to go. Thanks in advance,
    Robert

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