New motor

Discussion in 'Boat Modification Journal' started by 1 4 Fishing, Jul 16, 2009.

  1. 1 4 Fishing

    1 4 Fishing New Member

    Messages:
    76
    State:
    Oklahoma
    Guys I have a 1978 200hp Jonson my question are this motors any good. I got this motor given to me form a frind but he over heated it but i took it apart every thing looks good but i can not get it to pump water. If you all have any advice for me I would ippreciate it. Think you
     
  2. Iowa_Josh

    Iowa_Josh New Member

    Messages:
    1,463
    State:
    Central Iowa
    Did you pull the head? A man should really own a compression tester. I'd take the excuse to buy one. If that turns out ok, I'd buy the manual for that era of motors. Actually, I did buy one of the aftermarket manuals for 1950-75 or so J/E and it's one heck of a buy. I'll have cheap boat motors for the rest of my life. That's what I would do. Water pump parts really aren't too expensive. Especially when the motor is free.
     

  3. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    If by overheating you mean the motor was locked up or the cylinder walls were deeple scoured, that in itself would hve nothing to do with pumping water. Sounds more like the impellor is bad. Is it a good motor, darn betcha, just gotta get it fixed and take care of her.
     
  4. roadkill636

    roadkill636 New Member

    Messages:
    551
    State:
    warrenton misso
    what exactly do you meen you took it apart? have you removed the heads? lower unit? do the cylinder walls have any ring scratches in them. if you need an impeller I think I have one for that motor, I believe that the impeller was onlu used for 2-3 years, post a pic of the impeller keyway "CLOSE UP SHOT" I'll ship it to ya fer $20
    I ran this same motor for a while, I can tell you almost anything about it
     
  5. 1 4 Fishing

    1 4 Fishing New Member

    Messages:
    76
    State:
    Oklahoma

    Well i have puld the heads off there is no scoreing in the walls i have put new head gasket and exaust gasket water jacket gasket and putt a new water pump in it. it stell will not pump water any advice would help.

    o the compression is a 90 a piece
     
  6. crclhuk1

    crclhuk1 New Member

    Messages:
    291
    State:
    Central, SC
    Bryce, you have an excellent motor. Go to www.marineengine.com and find out anything on any engine you want to know about. This web site saved me a ton of cash and alot of headaches.
     
  7. roadkill636

    roadkill636 New Member

    Messages:
    551
    State:
    warrenton misso
    are you 100% certain that you have the water tube FIRMLY inserted into the water pump? did the water pump upper housing slide COMPLETELY down to the base plate? the key gets cockeyed sometimes and holdes it back sometimes,, It may take up to 45-60 seconded befor the water comes out of the exit holes after motor is started
    90 psi of compression is right for these crossflows. do you have the 1 5/16" or the 1 3/8" carbs? it will be casted on the front of the carbs?