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How to hold flywheel to remove flywheel nut??

B

Bill K

Contributing Member
Is there a special trick to jam that 40 hp flywheel while breaking the nut loose, I don't want to break anything
 
I think they make a specific tool, but I took a piece of rope, put a knot on the end, and wrapped it around the pull start. its not right in front of me, but either for the removal or the re-installation, I think the removal, you have to reverse the rope, to have the tension pulling in the right direction while losening the nut. You'll know right away if the direction is wrong.
 
a strap wrench will work, or a tie down strap, it is much easier to use an air wrench to remove the flywheel nuts.
 
Yes, the impact wrench will work without holding the flywheel at all - and yes, there is a special tool (flywheel holder), but the other suggestion - rope, strap wrench etc will work in a pinch
 
I will throw in a idea that has worked well for me, run one of the pistons part way down the cylinder and put a length of rope in the sparkplug hole then run the piston up. It will 'lock' the shaft and you can either loosen or tighten as needed. Be sure to leave the end of the rope hanging out, would be aggravating to have to fish around for the end after your done.
 
I’ve heard about this rope in the cylinder method before....no offence, but seems like a very dodgy way to hold the flywheel? Would not all the force be on the main barrings?
A strap wrench is only £10
 
It's a suggestion, you dont have to use it but you will need a very strong strap wrench to hold a flywheel against the pressure of either loosening or torquing the flywheel nut.
 
Exactly! Imagine all that pressure against the bareings.
I believe there is another tool that I think bolts to the block and locks the flywheel like a cog.
 
I am sure that if no one sells a ring gear locking tool that one could be made, I've done that on car engines numerous times. Btw, have you ever stopped to think how much pressure is on top of a piston when the fuel goes bang? It can be measured in TONS of pressure.
 
Yehh but that pressure =movement. Rope in cylinder =dead stop!
Not trying to be argumentative.....sometimes needs must & you’ve just gotta improvise. I’m with ya.:)
 
Swagonman------A simple strap wrench will hold the flywheel no problem.----To take the nut off and to torque it up.----Or a visegrip like tool with a chain.-----Homemade strap wrench will do it no problem !!!
 
I know that a chain wrench will hold the flywheel but I'm impressed that a strap wrench would have enough grip, since I've not tried it on an outboard i will have to accept the words of those that have.
 
Make one and you will know how they work.------You likely will find how to make one or buy one with a simple online search.
 
As I recall the torque spec on my 2002 90 hp Merc was 150 ft-lbs. Whatever it is for yours, expect to have to do a good job of holding the FW to get the nut off.
 
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