A10 won't start.

[Ewen]

Thank you Swarfy. Rotating that pinion doesn't look easy.....she is tight. The grooves in the pinion may are just are just out from the aluminium casing. Maybe I can get one of those bolt on affairs that I could tighten up into the grooves and then get a serious puller onto that. Dunno.... not a lot of room.
Will keep you posted.

[Ewen]

If I knew that the pinion was stuck in its current position for good I could  turn the cam pinion by hand to the correct corresponding position and see if the idler gear would slide in. I don't know that the pinion will stay put though.

[RDfella]

Certainly wouldn't risk running it with a sheared key.
Can you tap it around with a brass drift? The rotation idea was to find a spot where it is less tight in order to facilitate pulling it off.

[Rocket Racer]

Those pinions are a firm fit and usually require a firm pull to ease off, so if its managed to shear a pinion will be extremely tight. I wouldnt be looking to do anything but pull on it, you dont want to damage the crank, whereas a pinion is readily sacrificial. Heat, patience and if in doubt escalate and involve a capable engineer rather than causing damage. I think Swarfy had it right, be prepared to sacrifice the pinion gear. Hope to see a picture of the removed parts soon. I am concerned about the state of the crank/keyway there as this is normally a fit and forget part.

[Ewen]

Thanks Rocket Racer. I concur. I don't like the idea of trying to turn the pinion on the crank. I don't see how it could be done anyway.

[Ewen]

Are pinions available? Will the pinion pass through the timing side Bush?

[chaterlea25]

Hi Ewen,
It should be possible to wedge a piece of aluminium or brass between the gear teeth and engine case
Then turn the crank to get the sheared parts of the key inline, that would be the best place to exert a pull on it
I meant to take a pic of the puller jaws I made for extracting the pinion today , hopefully tomorrow?
No the pinon will not fit through the bush.
I would be reluctant to use a grinder on the pinion, the tiny bits are bound to get into the crank bush
You would most likely have to find a secondhand pinion

John

[RichardL]

Are pinions available? Will the pinion pass through the timing side Bush?

https://shop.srmclassicbikes.com/product/crank-pinion-gear-a7-a10-a50-a65

[Ewen]

Thanks RichardL.

[Rocket Racer]

might be worth getting a bespoke puller made to fit real snug and give you some purchase without spreading, that and heat!

[Ewen]

I'm making something right now. Must get the photo thing sorted.

[Ewen]

Thanks chaterlea25. I would really like to see your puller. I am playing around with a piece of 35mm box section at the moment. I plan to slide it on then clamp it tight with bolts. Will try and get a photo up when I get it finished.

[Ewen]

/img]

[Ewen]

This didn't work.... the puller legs are bending.

[Ewen]

The source of all my grief. This is where the offending piece of casting originated from.