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  1. #1

    Default Cough thump boat shake 35953A

    Hello again.
    Once again I need some help. My 35h evinrude 35953A is running like dung. In neutral it runs fine but in forward gear once you get moving good “fish finder” says about 7mph the motor performs a thump which physically shakes the whole boat, when this happens the water stops flowing from the nipple and stops coming out of the exhaust. Within the span of a second everything is back to normal except it keeps thumping. I guess coughing is more like it. Any suggestions? “I’ve replaced coil packs, spark plugs and wires hoping it was a spark issue. We’ve played with the timing and no results. Tried leaning out the flow and increasing it. Also today it would increase rpms without anybody being at the controls.

  2. #2
    Join Date
    Sep 2010
    Posts
    18,421

    Default Re: Cough thump boat shake 35953A

    Perhaps it is jumping out of gear.----Up to you to trouble shoot this.

  3. #3
    Join Date
    Nov 2011
    Posts
    2,636

    Default Re: Cough thump boat shake 35953A

    That would be my first thought also. Coming out of gear and immediatly slamming back into gear. And repeat. And repeat. Really, it is very common if that is what it is doing. Most people describe it as feeling like they hit an underwater object. Cause is a worn out clutch dog and forward gear in the lower unit.

    But, you say that water stops circulating. Now, that's a mystery that doesn't make sense..

  4. #4

    Default Re: Cough thump boat shake 35953A

    You guys are reinforcing my thoughts. I don’t want to dig in to it just on my own gut though. I’d hate to get in to the lower unit again (replaced parts when I bought it) only to cause another issue. Did notice at the time that the clutch dog was worn. I’ve got a friend whose been helping me bring it back to life as it absolutely didn’t run when I bought it. He’s screaming timing ratios off to cause it I’m saying gears (clutch dog) especially since it decided to not want to go into gear yesterday and throw itself out of gear. Thank you guys for your suggestions. I guess I order me a new dog and see what happens

  5. #5
    Join Date
    Sep 2010
    Posts
    18,421

    Default Re: Cough thump boat shake 35953A

    Tell your friend that the timing on these motors simply does not go out of adjustment.------Well , the flywheel key could be sheared and that does change the timing.-----Inspection testing on your part is required.----Are you sure the that gear shift linkages are properly assembled and adjusted ?

  6. #6

    Default Re: Cough thump boat shake 35953A

    When we originally rebuilt the lower unit we took it step by step in the seloc repair manual. If there was information missing we looked it up from multiple sources and used the common denominator from those varying sources. When I first purchased this motor it was missing several lower unit gear case parts which I ordered and we replaced. But I’ll insist we tear apart the lower unit again. I may even just say screw it and order the new dog and go from there. Thanks again

  7. #7

    Default Re: Cough thump boat shake 35953A

    What kind of conditions are the splines at the top of the driveshaft in? The water pump is keyed to the driveshaft, right?

  8. #8
    Join Date
    Apr 2010
    Posts
    4,705

    Default Re: Cough thump boat shake 35953A

    If you replace the dog, replace the gear also.

  9. #9

    Default Re: Cough thump boat shake 35953A

    Water pump is keyed to the shaft. And top of drive shaft was in good condition If I remember correctly.

  10. #10

    Default Re: Cough thump boat shake 35953A


  11. #11

    Default Re: Cough thump boat shake 35953A

    Hopefully that link works

  12. #12
    Join Date
    Sep 2010
    Posts
    18,421

    Default Re: Cough thump boat shake 35953A

    Classic stuff.------Jumping out of gear.----And now you need new dog and forward gear.------Also need to make sure linkages / rods are properly assembled and adjusted.

  13. #13
    Join Date
    Nov 2011
    Posts
    2,636

    Default Re: Cough thump boat shake 35953A

    No doubt about it, what racer said. I might add that letting that continue to happen will beat the linkage to death. Check carefully or you will just beat up your new $$$dog and gear

  14. #14

    Default Re: Cough thump boat shake 35953A

    Update: we tore into the gear case again today. Forgot how much of a pain that was. And the clutch dog was... wait for it... chewed to hell. Thank you everybody for your help with this. The forward gear had a little rounding on the leading edges but I’m thinking Of having it machined. Also thinking of doing the same with the rear gear. Again everyone thank you. Once I get this all settled I’ll post the finished product.

  15. #15
    Join Date
    Sep 2010
    Posts
    18,421

    Default Re: Cough thump boat shake 35953A

    Post # 1 says you played with the timing.----So that needs to be set properly again.--------Also make sure all shift linkages are properly assembled and adjusted.

  16. #16

    Default Re: Cough thump boat shake 35953A

    In the timing part we adjusted everything we could today but we’ll make final adjustments when it’s back together.

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