OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines How To Get The Crankshaft Nut Off?

I've got this old Victa mower two stroke I'm trying to get apart. Can't get the nut off the top end of the crankshaft or the big blob of metal off the bottom end.

Wonder if there's any trick to it? The nut should screw off, surely? The blob should also screw off, or needs pulling off?

I've had the blob in a vice holding the thing and a big breaker bar on the nut and still couldn't shift it.









Got pics up on google pics at: https://plus.google.com/photos/1107...2340917841478625?authkey=CPGc2Kqh0ZL5tQE

I've been asking about it on another forum, got directed here from there: http://whrl.pl/RdP1xh

Anyone got any clues?

use a rattle gun to loosen nut.anti-clockwise .its just too easy this way.
as for the big metal thing its a tapered sleeve on a tapered shaft and sometimes its very tightly on there.use a puller.if it wont budge and you are going to replace the bottom seal anyway you could heat it up.it will expand on the shaft and come off easily but you will probably cook your seal so try a gear puller 1st.

Hi there abrogard and welcome to the forum. Wow, normally a breaker bar would get that nut off fairly easily if held in a vice, try again and if it fails you'll have to go down to your local mechanic and ask him to zap it off for you with the rattle gun if you don't have one. As for the blob on the bottom (known as a "boss"), yes, it's a tapered seat so rest it on an anvil or a nice solid object like the top of a sturdy vice and give it a clean sharp blow on the side with a hammer. This should break the seal and it should just drop off. Good luck and let us know how you go.

Hi abrogard, and a warm welcome to the forum.
It's nice to welcome another Victa owner on board, as we all like to learn new things and tinker here!
Many thanks to Kempe an ODK member for directing you here.
Thanks also to gizmo and Bigted for their excellent advice....If you follow that, you should have no probs...

Once again abrogard, to OutdoorKing.

+1 to bigted re the boss [pullers rarely work on these, but impact always does], and Gizmo re the top nut [it's a normal right hand thread BTW].

I'd add that the top nut is usually the first thing to remove in a teardown of a Victa full crankshaft engine, preferably while the engine is still mounted to the chassis [better leverage].

If you want to get it undone with hand tools, you'll really have to reverse a couple of steps in your disassembly. Those being, run the nuts back up along the crankcase bolts [don't need to be super tight though], and reinstall the cylinder and head [don't need the gaskets]. Then you can pack the combustion chamber with rope/cord [the softer rope the better; cotton is ideal] fed through the spark plug hole, to lock the crank. This permits gripping the crankcase in a vise [not done up tight; just enough to engage the corner lugs fully is fine], and getting a breaker bar and socket on to the top nut to undo it.

From the description of the initial problem in the Whirlpool thread, I'd say that all that really needed to be done was to tighten up/replace the blade disc nut; the blade disc is just held tight by friction between the washer and boss; the boss lugs and the slots in the washer lock these two parts together.

There's a bit of a trick to getting that nut tight enough though; a rattle gun is the go. Or in the days before rattle guns were common, we used to use a big ring spanner, and hit it with a hammer for the final tighten, while hanging on to the the edge of the blade disc. My 1" AF spanner still shows hammer marks...

The nylon locking insert in the blade disc nut is obviously cactus, which is why it worked loose.

However, having gone this far, you might as well do the seals, and check the crankshaft bearings etc.

yep that's correct.so you have to loosen a RH thread anticlockwise.
rh on clockwise,, rh off anti clockwise

I did both the magneto nut and the boss recently on what looks like the same motor. If you havent got a rattle gun then the trick with both the magneto nut and the drive plate nut is to put a golf ball etc in the cylinder then put the head back on. Now the crank cannot turn. and a spark plug socket 13/16 is good for the magneto nut. To remove the magneto itself, put a lever both sides and push down. If the boss is seized onto the output shaft, use two equal hammers. Hit it on opposite sides at the same time and same force.