Recently installed a new chain and rear sprocket on the 250. Last week when I got off work, I noticed that nut to tighten the chain is loose and now it doesn't fit into the socket as the metal rod is bent (sorry, don't really know what the parts are called but please refer to the photos) would it be okay for me to just bend it back so that it would fit appropriately? I have no clue how it came loose and I think the reason why it's bent is because the chain probably hit it as you can see a small scuff mark on the corner of the plate.

The nut backed up and the rectangular part rotated until hitting the heads of those sprocket bolts.

You need an additional nut to fix this one in the proper position.
If the new nut cannot go over the bent rod, you could try straighten it with a hammer and a piece of hard wood.

Please see related recent thread:
http://www.ninjette.org/forums/showthread.php?t=34073

In general, repairs that involve hammers and/or putting things in a vise and bending them are not compatible with either safety or long-term durability.

http://cdn.carthrottle.com/wp-content/uploads/2013/12/clarkson-hammer.gif

Having said that, in this case bending it back probably won't hurt anything. The purpose of that assembly is to locate the axle prior to tightening the axle nut. It's not loaded in actual operation.

For future reference:

http://ecx.images-amazon.com/images/I/419LTsKt8cL._SL500_AA300_.jpg

Final word: If I saw something like this on a used bike, I'd pass. It's a sign that something went wrong that I as a purchaser don't want to deal with. So if resale is important to you, I'd just replace the part.

Have you tried loosening it a bit more then realigning it and tightening it back? Making sure to check that it stays even with the other side of course. I don't really see how that would happen in the first place though unless you tightened it without making sure it was alligned right after you popped the chain onto the new sprocket.

And yes, hammers make fantastic tools.

The nut backed up and the rectangular part rotated until hitting the heads of those sprocket bolts.

You need an additional nut to fix this one in the proper position.
If the new nut cannot go over the bent rod, you could try straighten it with a hammer and a piece of hard wood.

Please see related recent thread:
http://www.ninjette.org/forums/showthread.php?t=34073

Thanks Motofool but the nuts fits over the thread fine. It's the plate that isn't fitting inside the socket due to the threaded rod being bent. For as long as I can remember, the left side only has one nut while the other side has two. The left side (to adjust the chain) is supposed to have 2 nuts as well? I will try to straighten it out somehow to at least have the plate fit snug again. Right now, it's not fitting in at all. What caused the rectangular part to rotate?

They should both have 2 nuts.

In general, repairs that involve hammers and/or putting things in a vise and bending them...........

If you cannot fix it with a hammer, is an electrical problem :) :) :)

Thanks Motofool............
The left side (to adjust the chain) is supposed to have 2 nuts as well?..........
What caused the rectangular part to rotate?

You are welcome :)

Yes, left side should have two nuts: :crazyloco: + :crazyloco:

Vibration and lack of friction on the threads of the nut.

I think the reason why it's bent is because the chain probably hit it as you can see a small scuff mark on the corner of the plate.

Its bent because it hit the nuts holding in the sprocket. I usually silicone the left plate into the swing arm.

Thanks everyone. I will try to hammer it back to straighten the rod so the rectangular piece fits back into the socket. Then get a second nut after I align and check the chain's tension and probably use some loctite on it since I already have some

Thanks everyone. I will try to hammer it back to straighten the rod so the rectangular piece fits back into the socket. Then get a second nut after I align and check the chain's tension and probably use some loctite on it since I already have some

You are welcome. :)

I use a lock in my sprocket and more than once I have forgotten about it and have bent that threaded rod. :o
As many times I have straighten it.

What I try to say is that it is made of low carbon steel and it will stand several cycles of bending before breaking off.

If you prefer using Loctite, avoid the red one, which is for permanent locking, blue Loctite is much more easy to work with.

You are welcome. :)

I use a lock in my sprocket and more than once I have forgotten about it and have bent that threaded rod. :o
As many times I have straighten it.

What I try to say is that it is made of low carbon steel and it will stand several cycles of bending before breaking off.

If you prefer using Loctite, avoid the red one, which is for permanent locking, blue Loctite is much more easy to work with.

Thanks again. I have blue loctite since I use it for my scope rings on my rifles and are made to hold nuts in place so thats what i'll be using ;)

You are welcome. :)

I use a lock in my sprocket and more than once I have forgotten about it and have bent that threaded rod. :o
As many times I have straighten it.

What I try to say is that it is made of low carbon steel and it will stand several cycles of bending before breaking off.

If you prefer using Loctite, avoid the red one, which is for permanent locking, blue Loctite is much more easy to work with.

and once it does break off you can drill the hole out, tap it, and insert a threaded rod to replace the old one.

If you cannot fix it with a hammer, is an electrical problem :) :) :) Best quote of 2014 :thumbup: