mick
Well-Known Member
I recently sheared the (brass) pin in my Tohatsu 3.5 OB and the only replacement I could get was a stainless steel type. I know the arguments for each type but which do you favour?
Shear pins
- Thread starter mick
- Start date
sailorman
Well-Known Member
brass softer therefore less damage to the prop
duncanmack
Well-Known Member
Gearbox! forethought
Member
Shear Pin
I have had two Tohatsu 3.5 HP (one stolen).
The first had a brass shear pin - I could break that if I engaged gear with the engine RPM a little high. It did not need a rope around it to snap. I got so fed up with them I started making shear pins out of B&Q 'Brass' 4mm rod which is a bit softer than the original but about 20 times cheaper per 25mm length.
The current Tohatsu has a stainless shear pin. This hasnt let go despite the engine being stopped by assorted painters etc, and ploughing the mud on a few occasions.
I think the theory is that the moving parts mass of the engine is so low that stopping it via a plastic prop will not break anything. The shear pin is more a pain than a help.
I like the stainless pin.
It lets me get on with wrapping mooring ropes round my GK24's propellor instead.
I have had two Tohatsu 3.5 HP (one stolen).
The first had a brass shear pin - I could break that if I engaged gear with the engine RPM a little high. It did not need a rope around it to snap. I got so fed up with them I started making shear pins out of B&Q 'Brass' 4mm rod which is a bit softer than the original but about 20 times cheaper per 25mm length.
The current Tohatsu has a stainless shear pin. This hasnt let go despite the engine being stopped by assorted painters etc, and ploughing the mud on a few occasions.
I think the theory is that the moving parts mass of the engine is so low that stopping it via a plastic prop will not break anything. The shear pin is more a pain than a help.
I like the stainless pin.
It lets me get on with wrapping mooring ropes round my GK24's propellor instead.
fergie_mac66
Well-Known Member
Monel Pop rivet
I Couldn't find a spare shear pin For our little Honda 2.3 Found an several old Pop rivet shanks snipped to length make good shear pins. Got loads of spares now .
I Couldn't find a spare shear pin For our little Honda 2.3 Found an several old Pop rivet shanks snipped to length make good shear pins. Got loads of spares now .
reeac
Well-Known Member
I was faced with this quandary after I sheared a brass pin in my Mariner 3.3. The chandler offered brass or s.s.. I chose the latter and have had no subsequent problems. Seems to me that the manufacturer should supply a compromise which won't readily shear but will still protect the gears ... maybe the s.s. one does this.
