1979 chrysler thermostat

Discussion in 'Bubba's Outboards' started by Okccatman, Jan 28, 2006.

  1. Okccatman

    Okccatman New Member

    Messages:
    323
    State:
    Norman,Ok
    Got a question for you.
    I have a 1979 chrysler 155hp. I have done a few repairs to get it in good running order. But now I am having a problem with the thermostat or the impeller.
    I'll start off with the fact that I am a layman when it comes to outboards but I am pretty mechanical. And I do not have a manual for this motor. With that being said can you advise on how to test a thermostat. And also... is the thermostat on a 1975 55HP chrysler interchangable with this motor? I have a paperweight...I mean a 55hp that is a rebuildable/parts motor that is collecting dust.
    Thank you in advance.
    David Frantz
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    A thermostat can be tested by submerging it in water with a thermometer that'll read up towards the boiling point, 212 deg's at sea level. A candy thermometer will work. Don't let it touch the bottom of the pan.

    Put it on the stove in a pot of water and turn on the heat. Watch to see if it opens and at what temp. Should be near the 190 deg mark.

    I can't say for sure if the two thermostats are interchangeable, but you can compare sizes to see if they look alike and they might be.

    My guess would be the impellor first. Possibly both.
     

  3. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    David I would have to have the serial number off both engines to compare the T-stat compatibility. In the years they made those engines they would change one letter in the number and then change some small part to correlate to that.
    With that jargon said. Test the t-stat and make you a new gasket if it is okay and seal it and reinstall.
    I would do as bobpaul said I would replace the water pump.
     
  4. Okccatman

    Okccatman New Member

    Messages:
    323
    State:
    Norman,Ok
    OK Willard. Here are the numbers for both motors.
    The 1979 115 HP.....
    model= 1159h9c
    serial= 1532

    The 1975 55 HP......
    model= 555hg
    serial= 4496


    I am interested in the interchangability of a few parts.
    Thermostat
    Impeller
    Starter


    And if there are any other parts that you know of or come accross info on being interchangable please let me know. At this point in time I have a $250 mistake/paperweight with a 55HP cowling on it. And I would sure like to hear that some parts will work on the bigger motor. Thanks for your time in helping me and congrats on the award. You earned it buddy.

    David Frantz
     
  5. Okccatman

    Okccatman New Member

    Messages:
    323
    State:
    Norman,Ok
    OK.... I have pulled both T-stats and they are not interchangable. I have water on the stove right now to test.
    I would still be interesting in if the impeller and starter are interchangable.

    David Frantz
     
  6. Okccatman

    Okccatman New Member

    Messages:
    323
    State:
    Norman,Ok
    Another question about T-stats..... Would it hurt the motor or performance if I removed the T-stat and just allowed the water to flow all the time? And if so ... what would the difference be?
     
  7. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    You need to keep the T-stats because those engines were designed to operate at a given temp.
    It will run way to cool and them it will pump excess fuel thru it without burning it.
    What you would have then is a lot of plug fouling and eventually coking and ring breakage.
     
  8. Okccatman

    Okccatman New Member

    Messages:
    323
    State:
    Norman,Ok
    Sounds like a good reason to me. Thanks for explaining it.

    I am being led to belive that I made a rookie mistake. I initially thought a problem existed because I was not getting water thru the tell tale. I have inspected the T-stat and the impeller. Both appear to be fine.
    I am thinking that even tho the water intake holes in the lower unit were submerged that the water level may still have not been high enough to allow water to be sucked by the impeller. The lower unit is rather large and I was only able to submerge it apx 1 inch above the intake holes in the tub I was using.
    Does this seem like a posibility?
    Thanks
    David Frantz
     
  9. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    If you aren't getting any water thru the tell tell then take you a small length of wire and push it thru the tell tell. Dirt daubers love packing mud in those things. I have seen them do it over night while I was parked on the lake.

    Blow some air thru it also it won't hurt anything. It should have a warning horn to let you know if it is getting hot.
    If you don't know when the impeller was changed last then go ahead and change it. It will give you piece of mind.

    If you live close enough to water just back down to the water and submerge it that way,
    I have sat a 30 gal trash can under the lower and fill with water and raise the trailer tongue all the way up and it should have enough water.

    Do not rev that engine up when it is in the barrel though or on muffs.
     
  10. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill

    I don't know how I missed this post but when I get in from work today I will ck and see what is interchanable on each one. The difference in size isn't gonna let much interchange.

    As for being a paper weight or trot line anchor as I use to call them put it on e-bay and list the year and numbers and h/p Someone out there is looking for some of those parts.