I Really Need Help Removing This Sprocket

[bryantthenameles]

First off, I really hope I'm posting in the right section. I am at my wit's end with trying to get this sprocket off. I don't know much about engines at all so don't expect much knowledge on my part but I want to remove this and put it on another engine I have. The problem is that it wont come off no matter how much WD40 I use or how much I pry at it and hit it. I have removed the hex screw thing so that isn't it. The groove that the hex screw was in is blocked though. I tried sticking a cable tie through the groove to see if it would come out the other side but it didn't. The groove isn't just gunked up, it seems like a piece of metal is sitting in that groove, not that this would matter I don't think. It is pretty rusted so this is probably the issue. Also it has one round piece that spins around another round piece, hopefully you can see it in the picture. I don't know if it'll come off as one piece or what but I just want it off without breaking something. I'd be happy to supply and more information and any help you can provide would be tremendously appreciated.

Also, I am too tired to spell/grammar check so please forgive me.

 

[jman231994]

What you have is a centrifugal clutch, the inside expands to push on the outside when you rev it, so your kart wont move when idling. The piece of metal blocking the hole is the "key" it keeps the clutch and shaft moving together.

There might be grub/set screws around the back of the clutch where it is narrower, they will be allen key bolts and hold the clutch onto the shaft, you may have removed them, if thats what you mean by hex screw.

A trick that might make it easy for you if you know what your doing is to dismantle the clutch so you have just the solid centre shaft. Then you can use a propane torch to heat it up so it breaks the rust and loosens, or you might be able to use pullers on it then.

If the key in the groove has room on the other side to come out then you might be able to tap it out the other side with a punch, then you can rotate the whole thing to break the rust.

Other than that, your pictures didnt work. If you look at the bottom when you make a post in advanced mode theres an upload attachments section (advanced button is next to the post reply button when you have it written) . Add your photos that way, its never failed for me

EDIT: Ignore that, pictures are good now

 

[bryantthenameles]

Thanks for getting back to me so quickly. I just watched a video of a guy installing one of these and I see what you mean with the key. Did you mean punch it out from the front or from the back? There isn't much room at all between the back of the groove and the engine itself if that helps. Also, do I need the key out to remove the whole thing? I did mean allen key bolts before and I made sure they were out. How hard is it to dismantle the clutch? I had tried a propane torch last night but I will try again. I don't know if I'll be able to punch the key out since the lack of room so I'm not sure what my next approach should be.

I really appreciate the help, this means the difference between me having a running go kart and me throwing the engine out a window.

 

[fowler]

Just try to hit the key out the back a little

Once it has moved a little then it would have broken free

Honestly WD40 is good for f/a
U need some CRC or penertating oil

Anougther option is to soak the whole setup in deisel

Try to avoid using a pry bar they are good for destroying stuff
And try to avoid heat on the assembled clutch
It can cook some peices and warp others

 

[bryantthenameles]

Alright, I'll try knocking the key out later today since it's 2 am and I'll report back. Thanks

 

[jman231994]

No problem, were all here to help.

I meant knock it out if you can, it doesnt hold the clutch on, it just stops it from spinning freely on the shaft. So you should be fine with the key still in, just give it a tap like fowler said to free it up a little.

The clutch might have a circlip on the front around the sprocket, I cant see it in the photo. If it does then you just undo it and work your way through the clutch, pulling bits off as necessary til just the machined core remains, dont forget the order it went in though or you will struggle to get it back together. This should be fine to heat up. Dont apply too much force to it while its still hot, you might risk bending the crankshaft. Wait for it to cool off, maybe cool it with some water (not too sure if that will cause issues), and then try again to get it off

Good luck

 

[fowler]

dont shock cool it as u will either bend it or make it brittle

if u simply cant get it off then heat it in a line till it goes blue along the top

then let it cool and this will make it expand
but it will more than likely wreck it


oh read this post

u may be able to make this and pull it off
http://www.diygokarts.com/vb/showthread.php?t=18898&highlight=clutch+puller

 

[jman231994]

Thanks for that fowler, I'll remember that one

 

[OzFab]

You could try this

 

[Doc Sprocket]

Feel free to give it a couple of love-taps TOWARD the engine. Might help break the bond.

 

[Jonester 123]

I use a spray can of movit rust penetrate or pb blaster, most automotive stores should have it. Worked great for me on my camaro teardown, alot of real rusted on bolts etc. Spray it on and give it a few hours then whack it with a rubber mallet, do it a few times and it should break loose.

 

[bryantthenameles]

I hit the key from the front and it moved toward the back of the groove. There is probably no way to get the key out without taking the whole thing off.

I was actually brainstorming on how to make something similar to Fabroman's box so this guide could come in handy. I think I'll pick up some of this pb blaster and give that a try. Hopefully they have it or something similar at walmart, I'll check tonight if I get the time and I'll post back here again.

 

[bryantthenameles]

Oh, and I removed the circlip the other day.

 

[souperman000]

Oh, and I removed the circlip the other day.

Ahh, I was gonna say that. How far have you come taking it off? With the front snapring removed, basically the bell and teh shoes as well as their backing plate should have come off.

 

[bryantthenameles]

Ahh, I was gonna say that. How far have you come taking it off? With the front snapring removed, basically the bell and teh shoes as well as their backing plate should have come off.

It still won't budge

 

[bryantthenameles]

So I just want to make sure, if I buy the penetrating oil, will I almost definitely be able to get this thing off? I just tried again for an hour and let me tell you, I have honestly never been so angry in my entire life. I'm not even exaggerating. I'm a calm person and this has got me so fed up I thought I was honestly going to walk down the driveway with the engine and just throwing it as far as I can. It is almost to the point where it would be more satisfying to destroy the whole thing than remove the clutch. I managed to keep cool for now but if I don't get it off soon I will go insane. You have all been extremely helpful so far and what I just wrote is a little irrelevant but I am pissed. How effective is this penetrating oil?

 

[souperman000]

Its better than nothing, certainly than WD-40. Have you tried a gear puller?

 

[bryantthenameles]

I haven't tried a gear puller but I'd like to. They seem a little expensive for just this one task. I'm guessing I can't buy one at lowes or ace and then return it.

 

[Jonester 123]

So I just want to make sure, if I buy the penetrating oil, will I almost definitely be able to get this thing off? I just tried again for an hour and let me tell you, I have honestly never been so angry in my entire life. I'm not even exaggerating. I'm a calm person and this has got me so fed up I thought I was honestly going to walk down the driveway with the engine and just throwing it as far as I can. It is almost to the point where it would be more satisfying to destroy the whole thing than remove the clutch. I managed to keep cool for now but if I don't get it off soon I will go insane. You have all been extremely helpful so far and what I just wrote is a little irrelevant but I am pissed. How effective is this penetrating oil?

I have used movit penetrating spray and pb blaster for a very long time, works amazingly well. If it worked on my camaro that is over 30 years old of ruted on bolts, i am sure it will work on your go cart bolts or any seized up parts. You should get some from any automotive supply store.

 

[Doc Sprocket]

So I just want to make sure, if I buy the penetrating oil, will I almost definitely be able to get this thing off?

There are no guarantees in life, but it will improve your odds.

I haven't tried a gear puller but I'd like to. They seem a little expensive for just this one task. I'm guessing I can't buy one at lowes or ace and then return it.

Maybe, but it's a bit sheisty. Plus, stores like that don't carry such things in Canada, so I don't know if they would where you're at. On the other hand, many good auto parts stores RENT tools like that.

If that doesn't work out for you, then you're at a make-it-or-break-it stage. In that case, I would risk the clutch to save the engine. Take the outer snap ring off the clutch bell, and attempt to remove the bell. Lube if necessary. If the bell starts to come off and then hangs, there may be some mushrooming going on. Push the bell back on all the way, and use a file to carefully bevel the end of the sleeve it rides on. Once the bell is off, remove the retainer plate (if equipped) then shoes and springs. This leaves you with the bare inner hub. Now- whip out the hot wrench, and let 'er have it. Get the center of the hub (around the shaft) plenty hot, and immediately quench it in cold water, and lots of it. This "thermal shock" method is about as good as it gets for breaking a stubborn rust bond. I very much doubt that you will harm the shaft, but there is a fair chance you will warp the clutch hub. That's okay, because it's better to kill the clutch than beat everything so badly with a BFH that you end up hurting the engine.