Wodruff key

[wmc83]

Where can you buy one of these on a Sunday on the goldcoast?

[wmc83]

Whoops I ment woodruff

[smed]

Supercheap auto maybe?

[YZ250H]

A wise old parts man who sold me one for my 465 (from what used to be Moorooka Yamaha) told me I should always have a spare  )  I took his advice.

Sounds like there is a story to tell 

[Iain Cameron]

yea Yz250h ty Yamaha's go though them like wildfire then I moved to vmx Dt/Rt s eat them . allways carry a few in the box . Back to the problem wmc83 in the past Ive used any bit of steel made to fit (file ,grind, hacksaw ) then plenty of loctite shaft . hope this helps

[wmc83]

I even had a spare but do you think I can find the little bugger! I should have known better the crank and fly wheel have never been run together before and I haven't lapped them and after a spin around the block no start. I kicked it over so many times it looks like I polished the kick starter! so it Looks like I'll be cutting up a fallen tree tomorrow instead of riding  

[Iain Cameron]

don't miss out on a ride make one and use lots of locktite . what sort of bike wmc83?

[wmc83]

It's a 89 RMX250 apparently it's a common problem with them. Thanks for the advice guys but I'm going to be short on time to fix it so I'll fix it during the week might even polish the rest of the kick start so it matches

[YZ250H]

Ha ha - isn't that always the way....  Yeah I've got a spare one of those around somewhere 
Don't worry - I have even bought 2 parts the same off ebay 'cause I had forgotten I had the first one 

[Lozza]

It's a 89 RMX250 apparently it's a common problem with them. Thanks for the advice guys but I'm going to be short on time to fix it so I'll fix it during the week might even polish the rest of the kick start so it matches

It is just lap with valve paste, do the nut up with a rattle gun and forget the key

[pmc57]

If all else fails, make one. Typically they are about a R12mm radius so get hold of a peice of 25mm or 1" diameter round bar, measure the width of the keyway and cut with a hacksaw just over the width required, then measure the depth of the keyway in the shaft and add a couple of mm, scribe this dimension across the disc and cut again. The fiddly stuff happens next when you have to file the key to fit. Trick is not to make it too loose. Even mild steel will last well if it's not too loose a fit.

[tony27]

This is the site I used to make spares for my CZ when I was having issues with the taper, measure the width & go from there. Quite quick to make if you have access to a lathe

http://www.roymech.co.uk/Useful_Tables/Keyways/woodruff_keyways.html

[Bikeaholic]

When I've needed them I've been able to buy them from the Bearing Supply shop. They have a range of sizes available and cost stuff all

[EML]

The secret is in the lapping-not the key(woodruff) and not the bolt and certainly not the locktight.
A hint that came after a recent bout of flywheelitis was if you use Locktite-let it set for as long as you can-a week, a month, a year.

[chrisdespo]

Being a bit of a bike mechanic been in the trade over 35 years don't use loctite on these , sounds more to me like you dont have the flywheel tight enough check your tension.  the other problem that is common is the wrong sized key. to fit in the crank it must be a tight fit, really needs to be tapped in gently and must be snug in flywheel. remember that when you by from the machine shop or garage they may be metric or imperial if its not snug its not right.