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BS 375hp Throttle shaft spring control not working

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JBS375
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2024/08/21 13:56:42 (permalink)
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BS 375hp Throttle shaft spring control not working

Replaced carb diaphragm and gasket on BS 3.75 hp Model 096902 Type 7015, cleaned tank and carb. When put back together the Governor spring (PN 262757) does not move the Throttle Shaft, so the engine is at maximum speed.  Double checked the BS partlist and confirmed it shows just the one spring that I received in the repair kit, but this means there is nothing to physically move the Throttle Shaft to vary engine speed.
 
Looked at videos online for replacing the Governor spring on similar BS engines,  but they all show a second smaller spring connected to a vertical tab that apparently causes back tension on the Throttle Shaft to regulate the speed of the engine.  My engine has no such tab and I do not recall a second spring when I disassembled things.
 
Attaching photo and capture from BS Parts List document.  Appreciate any insights since engine runs but obviously I do not want to run the engine at maximum rpm all the time.

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    SRTsFZ6
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    Re: BS 375hp Throttle shaft spring control not working 2024/08/21 18:42:44 (permalink)
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    Your pic shows everything installed correctly.
     
    You don't have a separate tab (which is used on generators and some pressure washers) which holds a constant 3,600 RPMs.    You'll have one or the other, not both..   
     
    The linkage part that pulls on the spring adjusts the RPMs. 
    The tighter the tension, the faster the RPMs.
     
    Between the spring tension and the air flow over the "governor" (under the cover air flow pushes against
    the "flap") that's what sets the RPMs.  
     
    Again, when you adjust your moveable throttle, to TIGHTEN THE SPRING tension, the faster the engine RPMs...
     
    That engine does not have any governor INSIDE the engine crankcase pushing on a lever... 
    A very simple and effective set up..  
     
    Lastly, if you had JUST the TAB, and no moveable throttle, bending the tab, in a direction to put 
    more tension  on the spring, will raise the RPMs...
     
     
    .
     
     

    Scott
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    SRTsFZ6
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    Re: BS 375hp Throttle shaft spring control not working 2024/08/21 18:54:40 (permalink)
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    Circled IS you throttle.  Looking at your pic, it does indeed rotate:
     

     
    .

    Scott
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    JBS375
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    Re: BS 375hp Throttle shaft spring control not working 2024/08/22 11:20:47 (permalink)
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    Thank you for the quick reply and solution!  Had a photo mixup. The photo I attached was with the original spring instead of a shorter spring that came in the repair kit.  This morning took out the shorter spring from the kit and put back the longer original spring and control of engine speed instantly resolved.
     
    Thank you for sharing your wisdom! A big relief and the neighbors are happy my lawn is finally looking as it should.
     
    Happy mowing.
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    SRTsFZ6
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    Re: BS 375hp Throttle shaft spring control not working 2024/08/22 16:22:25 (permalink)
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    Glad you got it resolved. :)
     
    .

    Scott
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