What will I need to get sprocket to stay on countershaft? Please help (have pics)

[vic1616]

Hello, So recently i rode my 125 pitbike quite a bit at my friends farm. And on the second day, I did a late shaft in 3rd to fourth causing some **** to mess up (i dont think it was the gearbox thats messed) but basically I just felt the bike instantly go into neutral from 3rd. (or feel like it was) I was revving the engine but no movement.

I had it on the trailer and braught back, i undid the casing for countershaft to notice that 1 tooth chipped off, the chain off and the front sprocket was able to completely move freely along the countershaft. And I cant ride it like that because it will just fall off again causing the chain to come off or other damage to the bike.

So my question is, judging from the pics i put, what do i need to make the front sprocket snug on the countershaft without it sliding off. You will see it still had the bracket and 2 bolts but i dont know what the bolts are there for.

 

[zwebx]

Ahh i see what you mean, gimme two minutes [video=youtube_share;q6Iv8lZWMZo]http://youtu.be/q6Iv8lZWMZo[/video] (will be live soon)
dont know why i made a video but saw the oppertunity.. all thats bolted to your front sprocket is a locking plate (dont know the exact name sorry) and it goes on your splines on your engine and then turns a little bit then is bolted in place to stop the front sprocket sliding off

 

[vic1616]

Thanks for the video . But i do have that locking plate as you can see in my photos. Do i need a new plate? Or should i take the plate off the sprocket and reconfigure it on the coutershaft?

 

[my67xr]

when the retainer plate is bolted to the sprocket, the splines will line up opposite to the splines in the sprocket.
this holds the sprocket to the output shaft
the retainer plates do wear a bit and will eventually fail.

see on your output shaft, there is a groove cut in the splines
this is where the retainer plate locks into to hold the sprocket firmly onto the shaft.



there are a couple of different bolt patterns for the retainer plates
so when you go to buy another, measure yours first, across the centre to centre of the 2x bolt holes
there is also 2x different sized output shafts too, a 17mm or a 20mm, make sure you get the correct one for your bike.

http://www.ebay.com.au/itm/17mm-Eng..._Parts_Accessories&hash=item2ebd0b789b&_uhb=1
http://www.ebay.com.au/itm/Sprocket..._Parts_Accessories&hash=item2c65354c7c&_uhb=1


and finally, when you bolt the sprocket/retainer back together, make sure you use some good quality, high tensile bolts

 

[vic1616]

Thank you. So i guess i need a new retainer? Because even if i put it in the groove onthe shaft it still will be able to slide freely along it without locking in that one spot. Judging from the picutres does anything look damaged? And can be a easy fix?

 

[Blender]

yeh mate if its just the retainer it should be a simple as puttin it on, puttin the retainer thingo in the right groove, bolting it up and you should be off again. BUT if you've stripped the sprocket 'shaft', then your in a spot of 'bother' haha. im not sure as to wether you can but the individual shaft or not. m67xr or rotn50 should be able to point you in the right direction

 

[8r3nd0]

Yeah mate your retainers stuff by the looks of it it has ripped of the little tabs that hold it in that groove, eBay will have them as cheap as chips mate.

 

[Blender]

also mate, u obviously need a new front sprocket. so imo your should get a chain and sprocket set. that way you replace it now, instead of having to get them later. they will last a long time, and believe me, you'll have to get em eventually. grab a set of JT sprockets and a DID,RK, or renthal chain.

 

[vic1616]

thanks guys, i will get on getting a new front sprocket and chain. but i removed the bracket from my sprocket, heres a pic. is it worn? because i see the little indent on the sprocketshaft where you have to allign the teeth of the bracket at a certain spot in that groove where it locks. but when i try to put it in locking position i can never be able to align it with the sprocket so i can get the bolts back in.

 

[vic1616]

is there suppost to be 6 little teeth on the bracket? because mine still has 6

 

[vic1616]

or is there not suppost to be teeth? but instead whatever was inside the bracket to retain it fully ripped off?

 

[zwebx]

or is there not suppost to be teeth? but instead whatever was inside the bracket to retain it fully ripped off?

yeah, the 'bracket' or retainer was suppose to have a similar spline to that of your front sprocket therefor locking it in place.. they wear out but it takes alot of riding/no matenence

 

[vic1616]

yeah but when i put it in lock position between the grooves, it wont line up with the holes of the sprocket so i cant bolt it together

 

[vic1616]

i tried rotating the retainer so every time it locked on the shaft and every rotation i did that would make it lock would always be a little bit spread apart to where the holes line up

 

[my67xr]

as mentioned above-
when the retainer plate is bolted to the sprocket, the splines will line up opposite to the splines in the sprocket.

have you bought a new sprocket and retainer now ?


it will always sit with the teeth not lined up to the teeth on the sprocket
see the slot about half way along the output shaft
slide the sprocket and retainer onto the output shaft, hold the sprocket level with the back/engine side of the slot cut into the shaft.
then turn the retainer clockwise or anticlockwise to line up the bolt holes.
then bolt it together.

 

[vic1616]

ok problem fixed. i needed a new retainer. my other one was all worn but i need a new 14t sprocket and chain. how can i tell the length of my chain, do i count the connections?

 

[zwebx]

if you buy a pitbike chain you will get one thats too long and then you will have to break the chain and cut it down..
it can be done with a file, pin, flathead screwdriver/pliers and a hammer
or can be done easier with a chain breaker benchgrinder/file and some pliers/screwdriver

 

[my67xr]

yeah, count the amount of pins
then cut the new one down to suit.
i normally just buy a 136 link, and cut it down.
my local motorbike shop sells them for $25, they could probably shorten it to suit to if required, might cost an extra $10
take your old one with you.

or buy off ebay and diy.

 

[Blender]

yea grab a D.I.D or something decent. then buy some decent quality chain oil (the spray on stuff) and make sure its always oiled.