Trouble with my 70HP Johnson

Discussion in 'Bubba's Outboards' started by FloridaBoy, Mar 26, 2006.

  1. FloridaBoy

    FloridaBoy New Member

    Messages:
    17
    State:
    Florida
    I have a 1975 70Hp Johnson that I had to replace the powerhead on the powerhead that I put on it is a 1973 and is the same. I can get the motor to idle great but when I put it in gear it boggs down and stalls out can you help me out, do you have any suggestions? The motor is getting fuel and the carbs have been rebuilt. Could this be a timing adjustment or maybe a throttle adjustment?
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Who ever did the work should be able to assist you in this. Something could also be binding in the lower unit. You checked that?
     

  3. FloridaBoy

    FloridaBoy New Member

    Messages:
    17
    State:
    Florida
    Thanks for replying, I did most of the work myself the only thing I had the shop do was hook up the throttle and shift cables. I have checked the lower unit out it shifts into and out of both forward and reverse well and while out of the water the prop turns well in both directions while in gear. I put it in yesterday to check it out, it wouldn't crank up right away so I removed the cowling and moved the advance lever? conected to the throttle linkage and it started right up? This is why I think its a timing issue or a throttle adjustment?
     
  4. APD1146

    APD1146 New Member

    Messages:
    176
    State:
    New York
    Hey Bobpaul.
    I have a problem perhaps you could advise me on. I have a 1991 or 92 Force 3cyc. 70 hp. A few years ago the lower unit was all rebuilt professionally. It has always started a little slow but starts. Last year I took her out and she tried to turn over for about 6-7 seconds then nothing. After checking the fuses and all plug wires and found them to be good I then put the ears on her and turned on the water. No go, just 6-7 seconds. The starter was hot and I assumed bad. I replaced it with a new one and tried again with a fully charged battery. No luck! Again she would turn over for 6-7 seconds but then nothing. I felt the starter and it was hot as hell. It has been running real swell up to this point with the starter problem. I am beginning to wonder if it may have jumped timing? And ideas would be appricated. I have no manual for this engine, so most of the work is down professionally. I don't mess with things iI don't know.
    HELP PLEASE!!!!
     
  5. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Get a manuel and do a sink and link on it and see if that helps.

    To tell if a carb took a rebuild good is to do a trick an old wrench puller taught me is to take the air slincer off and start the motor and lay two fingers in the throat of the carb and if it boggs down then it is good to go. If it speeds the motor up then you need to check float adjustment or find out why the gas is not going thru it like it should.

    Every one calls them carbs on an out board where they really aren't. They are only metering devices.
     
  6. FloridaBoy

    FloridaBoy New Member

    Messages:
    17
    State:
    Florida
    Thanks I'll give it a try, do you know where I can get a manual for it?
     
  7. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    One other thing when you did the power head did you rebuild a power head or did you just buy one. I would look into the flywheel key and make sure it is not half sheared. This will make one act funney. Check every thing and make sure it is moving freely under the fly wheel.
     
  8. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill

    You need to start a new thread on this to keep down confusion.
    I would take the starter off and take it to a starter repair shop and let them check it. If its bad see if they will rebuild it. If not then good luck on finding one.
    Be sure all your battery and elect. connections between the battery and the starter are good and tight plus clean.
     
  9. APD1146

    APD1146 New Member

    Messages:
    176
    State:
    New York
    I took your advise and started a new thread on the subject. I did however as stated had the starter rebuilt.
    Thanks for listening.
     
  10. FloridaBoy

    FloridaBoy New Member

    Messages:
    17
    State:
    Florida
    I bought a powerhead, but pulled all of the parts off my original and put them on the new one, the key way and key for the flywheel are in good shape and everything under the flywheel moves freely. Also I went out and checked how you told me, with my fingers over the carbsit seemed to bogg down not speed up.:confused:
     
  11. Matt Smith

    Matt Smith New Member

    Messages:
    119
    State:
    Tennessee
    Do a compression check.
     
  12. APD1146

    APD1146 New Member

    Messages:
    176
    State:
    New York
    Can't do a compression teat if I can't get it to turn over any longer than 4-5 seconds. I don't remember as how I can do a test without the plugs in the other holes.
     
  13. Matt Smith

    Matt Smith New Member

    Messages:
    119
    State:
    Tennessee
    Huh???

    Please clarify how you get a compression check, and explain why you are replying to my suggestion to floridaboy.
     
  14. FloridaBoy

    FloridaBoy New Member

    Messages:
    17
    State:
    Florida
    Hi matt I performed a compression check before I installed the powerhead on my lower unit they were as follows #1-126lbs #2-122lbs & #3-124lbs. I've been doing some reading on what Bubbakat was saying about a sink and link and I think that might be what it is ????