'86 Mariner, Mysterious magnet

[Boatnut50]

I am rebuilding a 135 Mariner with the help of a friend. It is a 1986 model with the serial no of A910518, and is oil injected. I don't have any real history on the motor because it wasn't running when I bought the boat.It had no compression due to a bad cylinder but since the motor looked as clean as it did, we decided to try to rebuild it. After getting the necessary machine work done, we started putting the motor back together and this magnet appeared in our parts. This magnet is about 3/16" in diameter, and about 3/8" long. It also showed up with what looked like a half of a ball bearing of the same diameter. The half ball bearing seems to be made of plastic. Our question is where these two pieces may go, and do they possibly go together.

 

[dilligafda]

Re: '86 Mariner, Mysterious magnet

Hey Boatnut,<br /><br />I may be completely off the mark here, but check the coupler bearing for the oil pump. That engine has a rotational sensor for the oil pump that uses a magnet in the coupler to produce a signal for that sensor. If that's not it, I'm not real sure where to look! <br /><br />Good Luck!

 

[Boatnut50]

Re: '86 Mariner, Mysterious magnet

Thanks Dilligaf, I believe that you are right. It seems to fit there, and seems like the little half-round thing goes with it. We put the magnet into the hole in the shaft first and the half round thing on behind it so that the round part faces out.