• If this is your first visit to the iboats.com Boating Forums, be sure to check out the FAQ. To post a question or comment, begin by signing up. To start viewing messages, select the forum that you want to visit from the selection below.



Help Tip: If you have a question that has not been answered to your satisfaction in the archives, it is always best to start a new thread of your own. By starting your own thread, you will receive the maximum number of views by forum members.

Below are some additional forum policies in hopes of all iboats members will follow, Thank you.

1. Please do not reply to old topics or hijack existing topics. Old topics of a technical nature are like a library book, Please do not write in them.

2. Old topics should be considered archives and used for reference only. Please do not reply to them.

3. Do not take over someone elseís topic (aka hijack) with your own question, even if it is similar. If you have a question that has not been covered to your satisfaction in the archives, it is always best to start a new topic of your own.

4. If you have a question for the original poster (OP) and the topic is over 30 days old, send the OP a PM, he may not even visit the forums any longer, or may not notice your question in the old topic.

5. By starting your own topic, you will receive the maximum number of views by forum helpers that may not even notice your question when itís posted at the end of someone elseís topic. And those answers will be specific to your particular issue.

6. Please do not post to topics that have been inactive for more than 3 months unless you are the original poster. We have very active forums and any topic that remains inactive for that long should be considered "dead". It is especially confusing when there is an entirely new question posted to an old topic.

7. Posting at the end of any topic is considered to be hijacking the original posters topic which in turn subjects the topic to be closed if it continues to happen thus not making it fair to the original poster in the future had for some reason he/she needed to return for additional information or provide an update of the problem solved which is always welcomed within a reasonable amount of time frame.

8. Please note that you should see a red banner pop up near the bottom of each inactive topic asking you not to reply to old topics. The Red banner will read: Please note this topic has been inactive for 90 days. For the best results, please start a new topic.

Thank you all in advance for doing your part in helping iboats run a smooth ship.

Additional forum rules linked below.
See more
See less

shear pin breaking-25 hp

  • Filter
  • Time
  • Show
Clear All
new posts

  • shear pin breaking-25 hp

    I have a 1977 25 hp evinrude and the shear pin breaks frequently when I go from an idle into gear. Someone suggested to me that my idle should be adjusted. Any ideas?

  • #2
    Re: shear pin breaking-25 hp

    Just how fast is it idling cowfish? Welcome aboard!You should be idling down around 650 to 750 rpms. Does it "clunk" when you shift into gear? If so, the idle is high and can cause undue stress on the shear pin causing it to break often.Can you get a timing light with tach capabilities to take a look or maybe a tiny tach?
    When in doubt...use the manual

    Rayland, Ohio....Along the Muddy Banks of the Mighty Ohio River.


    • #3
      Re: shear pin breaking-25 hp

      The shear pin is just taking as much of the shock as it can, which it is designed to do to keep the gears from being ripped apart. When you shift that motor you have to reduce the speed completely back to shift (idle), then from neutral, shift firmly into gear.


      • #4
        Re: shear pin breaking-25 hp

        Also be sure you are using the right pins.OMC used different metals for different motors.DHP


        • #5
          Re: shear pin breaking-25 hp

          and if the engine is idling correctly check the pin hole in the propshaft for wear and the drive slot in the prop hub for excessive wear, both can shear pins when placed in gear if to sloppy.
          no tech questions by PM, they wont get answered.
          you have to be trusted by the people that you lie to .


          • #6
            Re: shear pin breaking-25 hp

            I had that problem untill I discovered that I was overtightening propnut. That nut should only be just tight, and turned to cutterpin holes are aligned, and locked with a cutterpin. If you overtighten you will notice the broken pins looks a bit bent ( though in pieces ) when you take them out. Take it easy.


            • #7
              Sign up today
              Re: shear pin breaking-25 hp

              thanks guys, you have been very helpful. This is a great discussion board that you have going here