The Jack's Small Engines Forum - Join Our Online Community
Reply to post

Tecumseh OHSK70 engine won’t rev

Author
hazzardous
Starting Member
  • Total Posts : 6
  • Scores: 0
  • Reward points: 0
  • Joined: 2023/12/26 15:11:57
  • Status: offline
2023/12/26 15:16:07 (permalink)
0

Tecumseh OHSK70 engine won’t rev

I bought a John Deere 724D snowblower non running.  The previous owner had definitely been messing with it.  It has a 7hp Tecumseh motor OHSK70.  The engine starts on choke but will not rev out on its own.  It dies when choke is off.  It will rev if I manually move the governor arm.  I’ve cleaned the carb, tried a second carb, adjusted the valves, tried a different coil, and adjusted the governor with no luck.  I’ve also verified the flywheel key wasn’t sheared.  Compression was 120psi.    I’m at a loss.  Any suggestions?  Is the governor broke inside the motor?

11 Replies Related Threads

    SRTsFZ6
    Super Member
    • Total Posts : 2074
    • Scores: 74
    • Reward points: 0
    • Joined: 2018/11/18 07:20:58
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:11:42 (permalink)
    0
    Is there tension against the throttle (engine off) from the governor arm/linkage?
     
    Did you adjust the governor with the throttle wide open and the shaft the goes into the engine
    twisted and locked down in the same direction as the carb throttle?
     
    Usually, when the governor breaks internally, the RPMs go way up above 3,600 RPMs.
     
    Does the machine have a throttle adjustment for the operator?
     
    .
     

    Scott
    SRTsFZ6
    Super Member
    • Total Posts : 2074
    • Scores: 74
    • Reward points: 0
    • Joined: 2018/11/18 07:20:58
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:15:06 (permalink)
    0
    Also, if you post the complete engine model # you can bring up a parts digram.
    Being it was messed before you got it, I'd bring up the parts picture and look for 
    any missing parts the PO left off, put on incorrectly, etc..
     
     
    https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/tecumseh/4-cycle-horizontal/ohsk-70 
     
     
    .

    Scott
    hazzardous
    Starting Member
    • Total Posts : 6
    • Scores: 0
    • Reward points: 0
    • Joined: 2023/12/26 15:11:57
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:17:09 (permalink)
    0
    There is an adjustable throttle on the snowblower. When the engine is off and the throttle is down there is no tension on the linkage. Yes I adjusted the governor with the throttle wide open. Before I start the snowblower and the throttle is on high the governor arm is maxed where I set it but once the engine starts it backs off if that makes sense. I tried tensioning the springs more as well
    hazzardous
    Starting Member
    • Total Posts : 6
    • Scores: 0
    • Reward points: 0
    • Joined: 2023/12/26 15:11:57
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:18:25 (permalink)
    0
    Ohsk70-72516d
    SRTsFZ6
    Super Member
    • Total Posts : 2074
    • Scores: 74
    • Reward points: 0
    • Joined: 2018/11/18 07:20:58
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:19:44 (permalink)
    0
    Just to be clear, with the engine off, is the governor pushing/holding the throttle wide open?
     
    .

    Scott
    hazzardous
    Starting Member
    • Total Posts : 6
    • Scores: 0
    • Reward points: 0
    • Joined: 2023/12/26 15:11:57
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:21:57 (permalink)
    0
    When the engine is off and the throttle is down the governor arm has play/is not holding the throttle wide open.
    SRTsFZ6
    Super Member
    • Total Posts : 2074
    • Scores: 74
    • Reward points: 0
    • Joined: 2018/11/18 07:20:58
    • Status: offline
    hazzardous
    Starting Member
    • Total Posts : 6
    • Scores: 0
    • Reward points: 0
    • Joined: 2023/12/26 15:11:57
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:23:48 (permalink)
    0
    Yes that’s my engine
    SRTsFZ6
    Super Member
    • Total Posts : 2074
    • Scores: 74
    • Reward points: 0
    • Joined: 2018/11/18 07:20:58
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:27:35 (permalink)
    0
    hazzardous
    When the engine is off and the throttle is down the governor arm has play/is not holding the throttle wide open.



    There should be tension holding the throttle open.
     
    The higher (more RPMs) you adjust the throttle, the stiffer the throttle will be with the governor. 
     
    Look at the engine pic's on the link, and see if your missing anything.
     
    .

    Scott
    hazzardous
    Starting Member
    • Total Posts : 6
    • Scores: 0
    • Reward points: 0
    • Joined: 2023/12/26 15:11:57
    • Status: offline
    Re: Tecumseh OHSK70 engine won’t rev 2023/12/26 19:44:46 (permalink)
    0
    If there is tension holding the throttle open when the throttle is down then there would be no idle adjustment or adjustment when the throttle is on high. Shouldn’t the stop on the butterfly of the carb be on the idle screw when throttle is down? Every video I saw on YouTube shows the linkage just like mine with the throttle down and up. Spring is loose with throttle down and tight at throttle up. The one spring going to the governor arm on mine does appear to have a bigger loop than a new one on eBay though.
    micl8
    New Member
    • Total Posts : 1
    • Scores: 0
    • Reward points: 0
    • Joined: 2024/01/02 13:53:15
    • Status: offline
    Flagged as Spam (1)
    Re: Tecumseh OHSK70 engine won’t rev 2024/01/02 13:54:56 (permalink)
    0
    WJ Smith Constructions stands as a premier choice among , bringing a fusion of craftsmanship and innovation to the local housing landscape. Renowned for their commitment to quality, WJ Smith Constructions goes beyond mere construction; they create homes that are timeless reflections of individual dreams. With a meticulous approach from concept to completion, they ensure that each residence is a unique blend of functionality and aesthetics. The personalized touch and attention to detail set them apart, making every home a testament to their dedication to excellence. WJ Smith Constructions doesn't just build houses; they craft enduring spaces that resonate with the spirit of Greenville, offering a harmonious blend of comfort, style, and sustainable practices. Choosing them means choosing a trusted partner in turning your vision of a dream home into a tangible.
    Jump to:
    Copyright © 1994 - 2016 Jacks Small Engine & Generator Service, LLC
    © 2025 APG vNext Trial Version 5.5