woodruff keys?

Question

hi guys i got a 1991 rmx 250 and the woodruff key disintergrated yesterday and i cant find a size guide anywhere anyone got any ideas wat size it should be thanks

its the flywheel rotor key believe me the state of the old key was beyond recognition the nut had come undone

i know i can go to dealership i wanted to make my own so was after a size to replicate

Answer 1

Get a piece of scrap steel, a file, a mall wise, some sand paper, and make a new one for yourself. Make sure it sits tight into the groove.

Answer 2

Go to a local hardware store and get them. You can go to the dealership and get a factory one for a few dollars. You need to know if it is half moon or square. Also if the key disintegrated there my be something wrong with the shaft as in seized or broken. If you go to the shop ask one of the mechanics they usually will help you out. Try using a dial indicator gauge to measure the slot in the shaft. Take a piece of paper, hold it over the shaft and rub slightly with a pencil, this will give you a very close image and you can measure the width from the marks on the paper.

Answer 3

The key should be a tight fit in the slot in the shaft, not to need hammering in, but to stay in place by itself and be free to turn to the right angle. It should just not touch the top of the slot in the other part. Normal running has the drive forces transferred via the mating surfaces, not the key, that's only there as an assembly aid and to prevent drift. If the key has disintegrated you may need to have the slots cleaned up and an oversize key made.

Answer 4

Don't try to make one yourself unless you have a fully equipped work shop, enough to make the key to the accuracy required and have all the necessary skills to do it. It is not just a case of getting any old bit of steel and getting it approximately the right size and shape. It may well have a radii on one side that locates into the groove on the end of the crank and this dictates the position and height it sits. The key also needs to be bang on size to stop things rattling about and then destroying itself again.

I do have all the tools, experience and equipment to make one should I want and I simply would not bother. Why are you so reluctant to buy one? It would be a gazillion times easier, faster and cheaper than trying to make on yourself.

Answer 5

Woodruff keys are designed to shear if overloaded. if you take the parts down to almost any light engineering company I'm sure you can get it sorted out in a flash. However, you need to find out why the key sheared in the first place..did it kick back on startup for instance or had the rotating parts become loose on the shaft? (or off the taper)

Answer 6

Try a local bearing supply company, they usually carry lots of different sizes. Also try a good motor factors or engineering supply company or maybe even a local cycle shop may have some.

Answer 7

I'm not sure, try a main dealer to find out what other engines use it and try and source a similar scrap engine to rob it from. Unusual fault though.

Answer 8

ace hardware has woodruf keys along with types & grades of screws & bolts in both metric & sae sizes if you dont live near a suziki dealer

Answer 9

Small engine repair shop or parts store or dealer for your mx250 should have a replacement---take the old pulley along to match.

Answer 10

Hi there
You need to give a bit more info as you have not said which key has snapped