G2 contact breaker end play

[Richard Hyatt]

Hi all,

another day another challenge!!

we have today tried to time the G2 - to no success - due to the advance retard assembly catching/touching the back of the contact breaker baseplate.

ok - we have a small amount of in/out end float on the camshaft(which obviously drives the taper) - and the contact breaker plate sits nicely in its little register(I am checking to see if its flat / not bowed in any way - but seems pretty flat).

we line up the bobweights as per book and then I noticed that the advance retard spring posts are perilously close to the back plate , leaving tiny little witness marks at the back.

clearly can't leave it like that

I am trying to upload some pics for you to see - have I the right parts?? we just don't know if the parts are correct .

apologies for pics - first time I have done this !!

thank you for any suggestions

updated - we've had the camshaft housing off the engine to check inside - nothing looked abnormal - what sort of end float is there please in/out on the camshaft and is there meant to be a shim to control it please - I think we had about 1mm maybe in/out

[Richard Hyatt]

Resolved

The bobweights were on back to front and inside out!

Unbeknown to us , but it didn't beat us !

[cbranni]

Nothing worse than back to front bob weights, good you found the problem tho.

Colin

[Richard Hyatt]

cheers
good fun this !!!!!

[Richard Hyatt]

Is there please a particular amount of end float of the camshaft please??
We had - what seemed a fair bit - of end float but no shims in the diagram shown

it would certainly be nice to know an acceptable end float figure or just not to worry!!

[Duncan]

If there is no specific information available the army service sheets are a possible guide: http://archives.jampot.dk/book/Workshop ... ndards.pdf

[Ozmadman]

If there is no specific information available the army service sheets are a possible guide: http://archives.jampot.dk/book/Workshop ... ndards.pdf

Different bike though.

[Ozmadman]

Is there please a particular amount of end float of the camshaft please??
We had - what seemed a fair bit - of end float but no shims in the diagram shown

it would certainly be nice to know an acceptable end float figure or just not to worry!!

There are no shims fitted. I fitted a new bush in my engine casing when I rebuilt my engine and with the bush flush with the casing there wasn't any end float as far as I can remember

[Richard Hyatt]

thank you for the suggestions - no shims fitted , we'll live with what we have , probably 0.5 - 1mm float .
by the time the oil is in there it'll hopefully quieten any float.
I suppose also , that any float will allow the followers a varying path over the can lobes.
thank you

[Duncan]

If there is no specific information available the army service sheets are a possible guide: http://archives.jampot.dk/book/Workshop ... ndards.pdf

Different bike though.

But still a sound starting point if you have no other information to guide you, they are both pushrod singles made by the same manfacturer.


In my opinion, if you run with 1mm ~40thou you will become aware of some cam noise as it slaps to and fro, if you search the history on the forum there will be discussions about it.