Magneto removal

[RogGillingham]

First post - not much mechanical knowledge - just taken ownership of Fathers old bike I want to get roadworthy. 1951 AJS 18S not started for 50 years but in not bad nick. Initially wanting to get it going so after some advice want to send magneto away for a refurb. Taken it off apart from separating it from the magneto chain; advice please of how to separate it.
Many Thanks, Roger

[clive]

Not quite sure how you have almost got it off without removing the magneto sprocket. You will need a two legged sprocket puller as trying to lever it will damage the chaincase. Once the sprocket is off the mag, attached to its platform, should withdraw. Welcome to the forum, it sounds as though you would be advised to join the club as your time as a guest is limited.
Regards

[Rob Harknett]

I would have first tried the mag. I've had bikes spent years in a field, mag was OK. 33 years later still start first kick. Never to even took the mag off or checked timing. Only cleaned points and made sure carbon pick up brush was free and clean wire connection

[RogGillingham]

Thanks for replies so promptly. I am a club member. Cleaned points, wasn't getting a spark on plug. Is the sprocket you talk about basically the sprocket around/behind nut I can see ,having taken the chain case off, that the chain goes round? I have taken all other fixings from the platform so it's just the connection to the chain that is preventing me removing it. Been gentle, don't want to damage anything! I have seen other posts about the two legged sprocket puller so will have to see about getting/making one. Many thanks again. Roger

[Eamonn]

..... I am a club member. ....

Roger, the Forum system doesn't see you as a full member and hence restricts what you can see/do on the Forum.
This is because you have a different username on the Membership system to that of the Forum.
I'll send you an email with further information on how we can resolve this.



(Later edit: All sorted now)

[Rob Harknett]

You said you cleaned points. you need to check more. take the lead out the mag, check the carbon brush / spring is OK free, making contact. e do the wire, eg wire through the little washer, splayed out so makes good contact etc. Check the plug cap, either by trying on a bike that's OK or by pass it by pushing a solid bit of wire in the lead /on the plug. Cleaning points only is not enough done to consider it is the mag at fault. Mag may work when you spend £'sss on it But may only be due to the fact you have had to do the things I mentioned in getting the mag overhauled. You may have only needed a new carbon brush and spring

[Duncan]

Roger, it is usually easier to remove the bottom cam sprocket first, I use a tyre lever about 10" or 12" long with a ? shape on one end, it usually pops off after applying leverage in a couple of locations behind the sprocket. Sound move getting the ancient magneto refurbished at this stage as it will only let you down later as the capacitor/condenser fail and the shellac melts in the windings.

[ajscomboman]

Roger, it is usually easier to remove the bottom cam sprocket first, I use a tyre lever about 10" or 12" long with a ? shape on one end, it usually pops off after applying leverage in a couple of locations behind the sprocket. Sound move getting the ancient magneto refurbished at this stage as it will only let you down later as the capacitor/condenser fail and the shellac melts in the windings.

Animal! You're such a cheapskate Moss! Get the correct tool, a nice little 2 leg puller does the job without the need for levers, if it's slim enough it'll slide behind the chain and just pop the whole lot off. My one does anyway. However when I can't find it, have I mentioned tyre levers work quite well.

[clive]

Roger, it is usually easier to remove the bottom cam sprocket first, I use a tyre lever about 10" or 12" long with a ? shape on one end, it usually pops off after applying leverage in a couple of locations behind the sprocket. Sound move getting the ancient magneto refurbished at this stage as it will only let you down later as the capacitor/condenser fail and the shellac melts in the windings.

But surely the magneto will not come off with the mag sprocket still attached. Yes cam sprocket using levers if he was just retiming, but to get the mag sprocket off so that he can have the mag refurbished should not be done with a tyre lever as it will probably crack the inner timing cover.

[ajscomboman]

Roger, it is usually easier to remove the bottom cam sprocket first, I use a tyre lever about 10" or 12" long with a ? shape on one end, it usually pops off after applying leverage in a couple of locations behind the sprocket. Sound move getting the ancient magneto refurbished at this stage as it will only let you down later as the capacitor/condenser fail and the shellac melts in the windings.

But surely the magneto will not come off with the mag sprocket still attached. Yes cam sprocket using levers if he was just retiming, but to get the mag sprocket off so that he can have the mag refurbished should not be done with a tyre lever as it will probably crack the inner timing cover.

Agree 100% I wouldn't use a lever on the mag sprocket despite what the workshop manual says! It's not as well supported as the engine sprocket and as you say Clive is highly likely to stress crack the ali case. A puller is recommended for this every time.