Outboard shear pin or not?

coromar

coromar

Well-Known Member
Joined
15 Dec 2004
Messages
119
Visit site
Hi All,

I was towing a boat with my dinghey when I seemed to lose thrust. the engine reved very well but the prop only just turned. I may have hit something in the water with the prop, but I didn't feel anything.

The engine is a Mariner 8hp Model No 8M built 1996.

Can anyone tell me if the engine has a shear pin or not, and where is a diagram of the bottom end of the engine.

Any help would be very useful.

Best wishes,

Paul
 
Hi there. certainly sounds like a broken shearpin. I dont know that engine specifically but if you look at the nut that holds the propeller on it will probably have a split pin through it. remove pin undo nut take off any washers that may or may not be there (put them back the same as they came off) Lift off the prop and the shearpin will be behind it ,through a hole in the propellor drive shaft,probably in bits.

Some engines instead of the shearpin have a rubber bush glued to the inside of the propeller, the glue holding this on is designed to give way if you hit something and allow the prop to free wheel. Take prop off and have a look. Let us know what you find.

You can in an emergency put a bit of suitable size stainless rod in place of the shearpin buit its better to get the correct part as they are built to shear off at the correct force anything else could be too weak or strong.
 
Last edited:
graham said:
You can in an emergency put a bit of suitable size stainless rod in place of the shearpin buit its better to get the correct part as they are built to shear off at the correct force anything else could be too weak or strong.
Click to expand...

Nails and all sorts will do BUT BE VERY CAREFULL and change for proper pin ASAP preferable use BRASS not stainless or next time you hit something you loose the inside of your prop not the sheer pin as designed.

Infact take prop off ans ask dealer, when you go in for new pin or prop :eek:
 
Consulting different parts lists to those in Lakesailors link I have come to the same conclusion.

A 1996 model does not have a shear pin ...Neither US made nor European made ones!
Therefore there is no point in looking for spare one!

The symptom of a "spun hub" is that it will drive at low power but slip when the power is increased.

You can check by marking the end of the prop shaft and the prop with aligning marks. Go for a spin and check the marks. If they no longer line up it confirms the spun hub

BTW you should be able to down load an owners manual from

http://download.brunswick-marine.com/download/main;jsessionid=105vjo07c1lcd?type=corp
 
Last edited:
Roberto said:
some outboards have a spare shear pin stored somewhere inside the top part, maybe remove the top cover and have a look ?
Click to expand...

Some boats with little 3.3 Mariners (for the jolly-boat) have three spare shear pins gaffa-taped inside the cowling, another dozen in the chart table drawer *and* a spare foot of B&Q brass rod in the garage.

After the owner read a post on here, and started making his own - one winter when bored with a hacksaw & bench grinder to hand ;-)
 
The leading experts on outboards concure that there is NO shear pin,thus it is the rubber bush on the prob
 
Thank-you

Hi All,

Thank-you for all your help with my problem.

I do have a slipping prop, no shear pin, just a broken bush. I will try to get a new bush fitted, or buy a new prop.

Thanks again, best wishes,

Paul
 
You must log in or register to reply here.

Share this page

Top