I see post about grinding the sprocket down when the chain wont fit etc...But I've not found (maybe I didn't look enough?) anything saying how much to take off. I don't want to take too much off that the chain doesn't fit. I'll be using a dremel for the job. Perhaps a cut off wheel if need be. Any ideas how much can be safely taken off? Stock 415 chain is being used. I would take the clutch lever/sprocket cover off but the screwheads were stripped out at the factory, so I can't get it off until I am able to get a kit to drill and tap it out.
How much to grind off?
- Thread starter foolsbike
- Start date
a hand impact driver will often get those screws off
grinding usually is done according to how much is needed to get the chain to fit
one needs to look at how the chain is acting as it is fed onto the sprocket - some sprockets have tooth tips that are a bit too wide and the chain roller won't clear it to get down into the trough - others have a lip below the trough that binds on the side plates of the chain preventing it from going all the way down
once looked at carefully, it should be clear what is needed
note: after a bit of running, chain will loosen up some, so getting at least a reasonable fit at first is usually enough later
grinding usually is done according to how much is needed to get the chain to fit
one needs to look at how the chain is acting as it is fed onto the sprocket - some sprockets have tooth tips that are a bit too wide and the chain roller won't clear it to get down into the trough - others have a lip below the trough that binds on the side plates of the chain preventing it from going all the way down
once looked at carefully, it should be clear what is needed
note: after a bit of running, chain will loosen up some, so getting at least a reasonable fit at first is usually enough later
It isn't so much taking off material as it is smoothing the factory rough edges. Some will tell you to "sharpen the sprocket teeth". That isn't necessary. The rough edges are what causes problems sometimes. Run your fingers over the teeth of the sprocket and you'll feel the rough edges. That's what needs to be removed.
As opposed to grinding I like to use a wire brush wheel on a bench grinder. That will smooth the teeth so they engage the chain more easily then make sure to keep the chain lubricated.
That's one man's opinion. You'll get others.
Tom
As opposed to grinding I like to use a wire brush wheel on a bench grinder. That will smooth the teeth so they engage the chain more easily then make sure to keep the chain lubricated.
That's one man's opinion. You'll get others.
Tom
Interesting...Thanks for the replies. It is hitting at the back. Doesn't look like I'll need to take too much off because the sprocket is fairly smooth. Although, the valleys look like that they can use some trimming and probably the chain will sit better then too. Just waiting on FedEx now to send me my Dremel...
I tell you what though, I just hope grinding the sprocket helps the clearance issue in the back. I think I may just replace the chain. Never had much luck with the stock chains anyway.
Oh, here's a pic. Yes I had circled the pin. I had to push it in and bend it. That caused a jam earlier.
Oh, here's a pic. Yes I had circled the pin. I had to push it in and bend it. That caused a jam earlier.
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Make sure that pin is at least flush with the cover. Some of them are held in place by a glob of epoxy. Some have been peened in place. I prefer the peen method but that means the pin might have to be shortened just enough to allow it to sit just below the surface where you can use a center punch to peen the aluminum over it.
While you're working in the area you might benefit from some info in this old thread > http://motorbicycling.com/showthread.php?p=465011#post465011
Tom
While you're working in the area you might benefit from some info in this old thread > http://motorbicycling.com/showthread.php?p=465011#post465011
Tom
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I have maybe a similar problem, but accessing the sprockets I have is not a problem.
FB, maybe you can get Allen Wrench Type Drive Bolts that could work instead of hex heads. I find that I try replacing all the hex heads in hopes it is a better way to fasten and unfasten without rounding off the heads. I have had to use Easy Outs, Super Outs, Bolt Outs... to remove rounded off stuff and it is better to avoid needing to do that. I realize that you got it that way, so I hope you get parts removed OK.
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What I am dealing with again:
I have a couple of sprockets that have sort of a squared off rather than more pointed ends and they are all for #35 chain.
The newest one I had quite a time getting the chain not to make popping sounds as I turned it manually with my hand. I finally got the two jack shafts at the right spacing apart for the tension and as best both parallel.
I did not hear nor feel it making and scraping or popping sound and tried it with the engine powered slowly and then full bore trail riding.
I had to remove one of the jack shafts temporarily when I put a new oil breather on the near by engine.
When I tried lining up the jack shafts to be parallel again I got it so it barely makes and clicks as the chain goes around.
I am thinking of trying the wire brush on the large sprocket that has the more squared off larger width teeth in hopes that I need not go back and keep trying over and over getting the jack shafts alignment again.
The more pointed tooth sprockets I have I did not have this problem so I think I should try this wire brush on this particular sprocket lightly and see if it helps.
MT
PS the first picture of the two sprockets held adjacent to one another and that are of the exact same number of teeth, are just to show how same number of teeth and both #35 type can look different, the shape of the teeth.
The second picture is my new sprocket 28 tooth, that I almost felt I would have better liked it in the smaller width tooth type, but it is what I bought and already used successfully on miles of trails.
The third picture has the lower sprocket being a wider width tooth type that the upper sprocket as you see how it is with chain on both sprockets.
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Okay, I ground the front sprocket down and the valleys but the issue is the chain is hitting the back of the case. Not the case where the clutch lever is that is removable but the back of the case where the magneto is. The chain is simply too large to fit and will not budge once it hits the back. There's maybe a (guesstimate) centimeter of clearance. It wont even fit. Not sure what to do now. Should I grind the case? I want to avoid buying another chain just yet. Which I will do eventually...
I often take the drive sprocket cover off and cut a small piece out right where the chain rubs - only remove just enough for clearance. Be sure to check while the cover is off that the chain is fitting all the way down on that sprocket too, as I've seen some sprockets with a lip below the valleys of the teeth that prevent the side plates of the chain from going all the way down.
I'm not following you on this. The chain can't hit the case where the magneto is. It can touch the inside of the clutch actuator cover. That was covered in the link I posted above.
Could you post another photo and show us where the chain is actually touching/binding?
Also keep in mind that a chain that is too loose (excessive slack) can wrap and bind on the engine drive sprocket. You'll want 1/2" to 3/4" of slack. No more, no less.
Tom
