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Any Ideas

Posted: Mon Feb 25, 2019 6:32 pm
by tstewart
I have screwed up or been screwed up, I got a set of reconditioned cranks have built the engine installed in bike and today went to install the points. Found 2 off cams to fit onto the crank (only need 1). Dragonfly pointed out I needed this but it is not on the parts list. Found two in the last of the parts I got in the box as the bike was a basket case. The keyway has been removed at some point on the refurbished crank, not something I have done.. So the cam does not lock on. I can see where the keyway was.

Any suggestions how I can over come this problem? Or does it need new cranks.

Re: Any Ideas

Posted: Tue Feb 26, 2019 1:42 am
by john.whiting
Do you mean that the end of the drive side main has been cut off.......or just the keyway is filled?.......even if the shaft is cut ,it can be repaired ,as the points take no load.

Re: Any Ideas

Posted: Tue Feb 26, 2019 7:59 am
by tstewart
John it looks like the metal on the crank has been ground off.

Re: Any Ideas

Posted: Tue Feb 26, 2019 8:01 am
by lawriewhite
Are both cams the same? By that I mean both have keyways, lobes in same position? If so, then for some reason you got 2 cams!!
How can you see where the keyway was? Has it been 'welded' & re-machined, if so, it can be ( very carefully ) centre-popped & drilled to take a small pin, & as said previously, no real load & more than enough to locate the cam.
Or, could it simply be a sheared key that's still in the slot & been 'smoothed' flush?
Either way, I'd have a go at drilling & re-pinning. An easy job, even in situ.

Re: Any Ideas

Posted: Tue Feb 26, 2019 1:22 pm
by simon.holyfield
tstewart wrote:John it looks like the metal on the crank has been ground off.


Could you take a close up picture?

Re: Any Ideas

Posted: Tue Feb 26, 2019 5:49 pm
by tstewart
My photography skills are almost zero, but here is a photo.

The keyway would have been at 9 o clock in the photo.

Been looking in the manual to see if there is a figure for below TDC and might go for electronic ignition as there would be less friction.
Cannot see the figure.

Hope the photo explains what is going on.

The 2 cam thing is because I bought the bike in bits and there was 2 of somethings.

Re: Any Ideas

Posted: Tue Feb 26, 2019 6:01 pm
by simon.holyfield
I think I'd drill that for a dowel or a roll pin, in situ.

Re: Any Ideas

Posted: Tue Feb 26, 2019 6:12 pm
by tstewart
Andy I had never thought about that, good idea. I will investigate that thanks.

Re: Any Ideas

Posted: Tue Feb 26, 2019 7:25 pm
by AndyEames
Try screwing the cam on to the end of the crank keeping the cutout on the cam lined up with whats left of the 'pip'. When the screw starts to get tight, check the alignment again and if ok,lightly tap the end end of the cam. No lump hammers !.Then tighten the screw home fully. As previously stated ,its the taper that holds it, the pip is only for timing.

Re: Any Ideas

Posted: Tue Feb 26, 2019 8:05 pm
by tstewart
Andy the pip is actually flat, but I suppose I could line the cam up with mark.