2007 Marlin Bowthruster Shear Pin

Meanwhile

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I got around to replacing the shear pin on my Side Power thruster. It is model SP55si-IP 12.

Here are a few photos to show the process. The longest time was finding the pins I'd ordered from Imtra a couple months back. They were in the last bag of tools in my shop!

So removing the sole and the gel hatch underneath are required for access. It was necessary to remove the table mount.

Access at 2 of the four 6mm hex head bolts was OK. I could see those bolts and they backed off with only a minor twist. The other 2 hex head bolts were hidden from view and they were a pain. The cover over the motor has sharp edges so wear gloves, unlike me.

I had the batteries disconnected while I'm also replacing the ribbed righing tubing to the motors so I didn't remove the power connections.

It was easy to pull the motor up and rest it on the lip of the hatch. The pin tapped in as per Imtra's instructions. No problem with getting the motor back on.

I saw on the web that a small ratcheting wrench is available for those hex head bolts. My hex socket set on a 1/4 ratchet could not fit on the bolt heads. If I need to replace the pin again I'm ordering that ratchet. Blind wrenching is not my specialty.20200317_121028.jpg20200317_121427.jpg20200317_121917.jpg20200317_125451.jpg20200317_132049.jpg20200317_132031.jpg20200317_132120.jpg
 

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Viking88rd

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Excellant post. We have a new to us 2007 Marlin. Saving this post for future reference.....just in case. Thanks!
 

Fishtales

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Did the pin break or was it preventative?
 

Fishtales

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Curious as I've never had an issue with the pin. I do change out the zinc every year.
 

Meanwhile

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Curious as I've never had an issue with the pin. I do change out the zinc every year.
The pin broke. I think I reversed direction without allowing the motor to stop. It is only 4mm so it can go quickly. I had input from a mechanic about a boater that broke several shear pins. He was not careful.

The pin behind the propeller is made of stronger material and I've heard it rarely breaks.
 

Fishtales

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Thanks. Makes sense that it has one. Don't forget to change the zinc yearly. It is aluminum and really corrodes quickly (at least on my boat). I get them from boat zincs on line with them for the outboards. I've seem a few GWs with missing blades and corroded propellers because people don't change the zincs enough.
 

Meanwhile

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Yes, the zinc goes quickly on mine also.
Talking of zincs, my trim tab zincs also go quickly. I started buying zincs from Bennett instead of tear drop style.

20200321_203109.jpg
 
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HMBJack

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You are correct about it being really hard to get those allen bolts out.

If you or someone else has a link to that low profile ratcheting wrench - please do post here.

I wish to buy one and place in my on-board tool bag along with my spare shear pin.
As anyone who has done this - getting those allen bolts out is 70% of the effort!

Thanks!
 
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Meanwhile

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You are correct about it being really hard to get those allen bolts out.

If you or someone else has a link to that low profile ratcheting wrench - please do post here.

I wish to buy one and place in my on-board tool bag along with my spare shear pin.
As anyone who has done this - getting those allen bolts out is 70% of the effort!

Thanks!

Here is just the ticket , screen shot with part number.Screenshot_20200326-224131_Chrome.jpg
 
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Meanwhile

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I can testify that the mini-wrench makes changing the shear pin a snap. I'm down to 30 minutes for the job. That includes wrapping the pin holder 3 times with black tape. The hole has enlarged so much the pin will fly out and break. No tapping is required to put the pin in now.
 

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