Jubilee timing cover withdrawal bolt 25016

Previously wrote:

hi there, im currantly restoring a norton jubilee engined grasstrack hillclimb bike ,im at the stage of removing the timing cover ive removed the domed timing cover removed the contact breaker assembly and seperated the cable connections i now require a withdrawal bolt 25016 as stated in the manual where can i purchase one of these bolts ? any info would be gratefull

Tez,

Believe the Message from Steve Kilbey on "Navigator auto advance unit" as answered by Al Osborn on 14th Jul 2011 is same problem as this - so please read that, as well as below.

After removing Contact Breaker Cover (2 screws) and the two posts under this cover, remove the centre bolt for the auto advance unit and pull the cam towards you, off its post and extract the cam [you may need to open the points unless you've already taken these off the contact breaker plate(s)]. Remove the top and bottom screws that go through the contact breaker plate(s). This frees off the top half plate and the bottom full plate. Remove the plates, this reveals the auto advance mechanism (Advance/Retard Unit) which is held into and extended part of the Inlet Camshafton a taper.

A special tool is not really required unless the A/R Unit is rusted or seized into the taper. All I have done in the past is to loosely replace the centre bolt down into theA/R Unitand using a block of wood and hammer (or a small hide mallet)GENTLY tap the protruding post of this unit from the side, near to the head of the bolt. Do this from either side a couple of times and the Unit should be shocked free.

Trust this helps

Regards

Brian

Hi Tez, I had this problem on my Navigator. The "special bolt" isn't available but easy to replicate. You will need to use an old 1/4 inch Whitworth bolt, (one of the old engine casing screws will do if you are replacing them a part of the restoration)

Screw this into the end of the camshaft on which the advance mechanism rotor is held by the taper. Mark the bolt at the point where it exits the rotor and them remove it.

Cut the bolt 1/4 inch shorter than the marked length and then use a hacksaw blade to cut a slot in the end big enough to accept a flat screwdriver (this is to allow you to unscrew it after he next step)

Screw the (now headless) bolt back into the camshaft again, and then screw the centre bold back into the rotor, as you tighten it will push on the headless bolt and push the rotor off of the end of the taper. It will suddenly give and pop off when the torque is high enough, so be prepared!

You can now use a screwdriver on the headless bolt to remove it from the Camshaft

Good luck.

Paul