Front Sprocket Removal

First off, I have a 1981 KZ440 LTD.
Like many other people on this board, I'm having trouble removing the front sprocket. From reading posts in the archive, I've learned that the sprocket nut is a regular right-hand threaded nut and the socket size should be 1 1/16th and it will require a ton of torque to get this sucker off and it's best done with an impact wrench.

What I don't know is how in the world to get the sprocket to hold still. I kept the old chain on and attempted having someone stand on the rear brake while I torqued away on the nut, but this resulted in bending the torsion arm that holds the rear brake in place. There is a hole in the sprocket that looks like you should be able to put a drill bit thru and lock it into place on the engine, but it doesn't look like it lines up with any holes on the engine. The clymer manual says something about fashioning a sprocket holding tool using the old chain and a piece of wood, but I don't know what that means. Anybody have any experience with this?

One more question - the sprocket nut looks like a double nut - 1 1/16th and then a 1 1/4th behind it. Are these nuts two separate nuts? Or are they one nut together?

I take it you dont have a impact, not the best thing but you can put a load on the breaker bar and then hit it with a hammer, the shock acts like a impact

hold front and rear brake,long cheater pipe

rhinoboard wrote:

First off, I have a 1981 KZ440 LTD.
Like many other people on this board, I'm having trouble removing the front sprocket....

What I don't know is how in the world to get the sprocket to hold still....

fashioning a sprocket holding tool using the old chain and a piece of wood, but I don't know what that means. Anybody have any experience with this?

One more question - the sprocket nut looks like a double nut - 1 1/16th and then a 1 1/4th behind it. Are these nuts two separate nuts? Or are they one nut together?

If I remember correctly, it's a single 27mm nut, and there should be a lock-washer behind it. Perhaps the tabs/edges of the lock washer that are folded over are confusing you?

The Clymer reference probably means that if you jam a block of wood between the chain and sprocket, the sprocket can no longer turn (since the wood cannot trravel around the sprocket *with* the chain). I guess. I don't know...

Here's what I posted a while back on the "Kawasaki Twins" forum about this very situation...
Link to post

No, the lock washer's not confusing me, I already have that flattened out. I'll try to remember to take a pic of the nut when I get home. I thought it might be a jam-nut, but the sides of the nuts all line up, which would be very rare with a jam-nut. So I am thinking it is just one nut with 2 sizes on it.

One of my bikes has a sprocket nut like you describe, and yes, it is a single nut with two different sizes.

If you have mag wheels, you can insert a strong piece of wood (I used an old baseball bat) through the wheel, and let the wheel turn forward until the wood is locked against the frame. Then use the right sized socket wrench with a 4 foot length of pipe sliped over the handle for leverage. Also, it helps to heat the nut first with a propane torch, for maybe 3 minutes.

Let us know how you make out.
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rhinoboard wrote:

...sprocket nut looks like a double nut - 1 1/16th and then a 1 1/4th behind it. Are these nuts two separate nuts? Or are they one nut together?

Am guessing this is not the OEM (stock) nut, and hoping it's not a wrong-sized cross-threaded situation and that the shaft threads are undamaged. Would replace with correct nut after cleaning up the shaft threads. Might consider using nut splitter or cutting off with dremmel (could go part way through then delicately use hammer and chisel). Be careful not to damage the shaft. Idea is to remove the incorrect nut by any means possible without damaging the shaft or threads on the shaft. And please wear protective goggles.

Turning nut counter-clockwise to remove it -- right?

Good Luck!

EDIT -- Again I have learned from apeman. Glad to hear it's the correct nut.

Post edited by: Patton, at: 2007/06/27 14:17

Post edited by: Patton, at: 2007/06/27 14:51

If there's a friendly local tire repair store in your area -- ride or carry the bike in (bring with you the correct size 1/2 inch socket) and ask for a favor. They may be happy to oblidge (perhaps consider it a challenge and pleasant change of pace with opportunity to create good will toward you as a prospective automobile tire customer). A $5 tip would be in order for the guy and his air impact wrench. Don't forget your socket.

Worst case scenerio -- friendly advice to GFY.

BTW, is reason for removal being to replace an obviously worn out countershaft sprocket? Just asking because for whatever reason the same countershaft sprocket often seems well able to continue serving on through a second rear sprocket.

Good Luck!

Patton, If the nut requires a 27mm socket to remove it, it is very likely an OEM nut. The reason is that the nut is actually 20mm and the STANDARD size for a 20mm nut is actually 30mm socket. The problem with a standard nut of this size is that you will have a hard time finding one that isn't to thick. I buy thin 20mm nuts with 30mm outside size that are thin enough to use on the countershaft sprocket. The OEM lock washer is large enough where you can just bend the edge over. If you buy a number of these large 20mm nuts, the cost is low so you can pretty much use a new one whenever you need to. Most are hacked up badly from folks trying to turn them off with a chisel or something.

The parts diagrams even show the 'nut with 2 sizes'.
It is a 20mm nut.

Impact Wrenches have got to be the best tool ever created!

I was able to hold the sprocket still by putting the old chain back on and then sticking a piece of pipe between the thick spokes on the back wheel and the frame (I have the super thick, 5 spoke rims). I had the socket and got a 4 foot extension pipe to add on to my breaker bar. Still no luck.

After asking just about everyone at work if they had an impact wrench, I finally came across somebody who did. I fired that thing up last night and the nut came right off! If anybody else is reading this post trying to get the sprocket nut off, just give up whatever you are trying to do with a regular breaker bar and socket and just ask around until you find somebody with a good impact wrench. It is unbelievably easy with the impact wrench.

Thanks everybody for your advice!

Impact wrenches are worth their weight in gold.