Motor Rebuild/Restore

Discussion in 'Boat Modification Journal' started by BKS72, Sep 9, 2008.

  1. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    I thought about posting this in the outboards section, but it's more of a project than a repair question.

    I blew the wristpin bearing in the #2 cylinder of my 1980 Evinrude 75 on Labor Day. I've got it all tore down, cleaned, and painted and got parts ordered today. Hopefully we (Mo.Hick and I) will start putting her back together this weekend.

    When the bearings grenaded they destroyed the #2 piston and head and scored the cylinder wall. The block is at the machine shop getting bored .030 over to clean up the cylinders. The rebuild kit I ordered has all bearings (mains, rod, and wristpin) as well as new oversize pistons (all 3) and rings and all gaskets and seals. I also ordered a new connecting rod to replace the one the bearing went out of and the gelseal and gasket sealer needed.

    I found a head on Ebay pretty cheap and ordered a set of Boyesen power reeds and carb rebuild kits as well. Just over $800 in parts so far and the machine shop work should come in around $150. Not real cheap, but cheaper than a reman powerhead and I get the fun of rebuilding it:big_smile:

    While I was waiting on parts, we changed the water pump and disassembled and cleaned and painted the LU and exhaust housing and covers. I also sanded down and painted a spare cowl I had lying around.

    Attached pix are of the damaged piston and head as well as before and after pix of what's been done so far. More pix to follow as we rebuild it. Enjoy!

    Branden

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Branden looking good. I hope you took plenty of pictures on the tear down to help with the reassemble. Take your time and torque it all and do the torquing in two stages and also if the head gasket is shiney then don't put any sealer on it just added a thin coat of oil to it.
     

  3. bluejay

    bluejay Well-Known Member

    Messages:
    8,507
    State:
    Napoleon, Mo.
    Will be following this post. Thanks Branden.
     
  4. CountryHart

    CountryHart New Member

    Messages:
    10,914
    State:
    missouri
    Looks like your own the right track:wink: I started mine sunday evenin but still don't know why it locked up to begin with. I'll figure something out, and keep us posted with yours. Also is the yellow lower unit painted or primer?
     
  5. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    The lower is painted yellow - thought the ol' girl needed some color:wink: John, are you sure you just didin't shut yours off and PRETEND it locked up so you could stay out longer??:smile2: Just kidding man, hope you find it and it's something simple (and cheap). How's the compression on it? And have you checked the gearbox to see if something hung up in it?
     
  6. Skunk Master

    Skunk Master New Member

    Messages:
    3,366
    State:
    Colinsville, Il
    I sure hope you know where all them parts go.. This is not one of them projects where its ok to have extra parts when done... Good Luck buddy..
     
  7. CountryHart

    CountryHart New Member

    Messages:
    10,914
    State:
    missouri
    John, are you sure you just didin't shut yours off and PRETEND it locked up so you could stay out longer??


    Actually i do have buddies that own the dock and marina.:wink: Bad thing is he wants to sell ya a new ride. I can't afford junk, let alone a new one.:crazy::crazy::crazy: Talkin with bubba on pm and he's helpin me too, i'll get compression tomorrow evenin. All i know is i put the plugs back in her and she sounds like ole' Whitie. I got my fingas crossed.
     
  8. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    Bad news - majority of the rebuild kit didn't ship till today and the connecting rod and gasket kits have to come out of Florida:sad2: Hopefully my carb kits and reeds come in tomorrow so I can at least get the small stuff out of the way before my other parts get here.
     
  9. arkrivercatman

    arkrivercatman New Member

    Messages:
    4,472
    State:
    KS
    Good Luck Branden!! The paint job looks good! I am confident that you can do it!
     
  10. Brentkeele

    Brentkeele New Member

    Messages:
    445
    State:
    Nokomis, Illinois
    Good luck Branden. Looking good! keep us posted!
     
  11. thegavel

    thegavel New Member

    Messages:
    1,317
    State:
    West Des Moines, Iowa
    Looks and sounds like you are on the right track brother.... Keep us posted!
     
  12. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    Got my replacement head in today - $49.95 on eBay with shipping and it looks perfect, so I can't complain.:big_smile:

    New Boyesen Power Reeds also came in and I got those installed. Dunno if they'll make all that much difference, but they are cool looking:wink:

    Old metal reeds:

    [​IMG]

    [​IMG]

    New composite reeds:

    [​IMG]

    [​IMG]
     
  13. dougc

    dougc Active Member

    Messages:
    1,711
    State:
    Independen
    Good luck with your project Branden-hope she runs better than new!
     
  14. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    Got some more parts in today. Still waiting on my block to get finished at the machine shop and a gasket set and connecting rod that are coming out of Florida.

    I'm in CA all next week, but hopefully by the time I get off the plane on Friday all my stuff is in and we can put 'er back together on Saturday. Should be like I went back in time to 1980 and bought a new motor when it's done - only things original will be the castings, crank, and 2 connecting rods:wink:

    Here's what about $600 worth of bearings and pistons looks like:eek:oooh:
     

    Attached Files:

  15. Brentkeele

    Brentkeele New Member

    Messages:
    445
    State:
    Nokomis, Illinois
    Any new progress on the motor Branden?
     
  16. Trevor1

    Trevor1 New Member

    Messages:
    546
    State:
    oklahoma
    You might want to make sure you fix what caused the bearing to fail in the first place, generally when these fail it's from a lack of oil. Does this motor have direct oil injection, or do you mix it with the gas? If it's a premix somtimes a cylinder won't get fuel and in a 2-stroke this also means no oil. Good luck on the rebuild
     
  17. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    Got my block and rest of the parts I was waiting for this week - I've got to head to town in a minute and pick up a couple of odds and ends and then I'll start putting her back together. Just got back from CA late last night, so between waiting on parts and being out of town I haven't got much done. Pix to follow this evening!
     
  18. Brentkeele

    Brentkeele New Member

    Messages:
    445
    State:
    Nokomis, Illinois
    Looking forward to it:cool2:
     
  19. Brentkeele

    Brentkeele New Member

    Messages:
    445
    State:
    Nokomis, Illinois
    I just went back and looked at your pics of the motor and I gotta tell ya, I'm kinda digging that yellow lower unit!!:smile2::smile2:
     
  20. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    Hit it a pretty good lick today. Got a late start because of some kid duty this morning and a trip to get the odds and ends I mentioned earlier. Odds and ends consisted of ring compressors, ring spreaders, torque wrench, and other assorted stuff I've been putting off buying till I got all my parts in.

    Got it about 80% assembled. It's actually been pretty enjoyable. I was having so much fun I just now realized it's 4AM:eek:oooh: Gotta put the linkage back together, put the wiring harness back on, and rebuild and install the carbs and after that it's just bolting it back down to the lower unit and seeing if it'll run:wink:

    Sorry there aren't a whole lot of pix of it going together, but if you've got a Clymer or other manual you've seen it before:smile2: If it'll run as good as it looks I'll be in good shape:cool2:
     

    Attached Files: