I currently have a neighbour's 350 Bullet Trials bike in my workshop for fettling .
Long story short - the neighbour (who has owned the bike on and off since the early 70s) handed it to a friend for sorting . . but the friend is going through a bad patch and let him down - so I got the (unpaid) job.
The bike was constructed in the late 1950s from 'Factory Special' parts by 'Bell & Small' an Edinburgh MC Dealers. It competed in various trials over the years until it was ridden in the 1962 SSDT by Eric MacNamara under No. 190. Eric represented the 'Edinburgh & District motor Club'. This is a Special machine and differs from the 350 'bullet' of the time.
The bike has a BTH 'TT' magneto, with a broken advance/retard cable. The reason the cable broke (I assume) is that the slip ring was seized. I have stripped the contact breaker assembly down.
I have been searching the net for details of this Mag, but haven't found much apart from some pictures of complete units and sites offering Magneto Refurbishment.
The problem I have is that there is a steel plug with a small steel peg that fits through the side of the bronze housing. The peg fits a slot in the slip ring and limits the ring's rotation. The peg is offset and may possibly be rotated to provide fine adjustment to maximum advance or retard. It has been abused by someone in the past and is fixed solid.
I need to remove this plug in order to 'lap' the slip ring into the bronze housing to restore easy, shake-free movement. Heating and tapping with a drift hasn't worked and I don't want to be brutal (yet). This Mag is over 60 years old.
I need an exploded diagram . . before I find the exploded bits in my hand .
Does anyone have details of this 'TT' mag, or a link to such ??
Any clues gratefully received.
Bob.
Long story short - the neighbour (who has owned the bike on and off since the early 70s) handed it to a friend for sorting . . but the friend is going through a bad patch and let him down - so I got the (unpaid) job.
The bike was constructed in the late 1950s from 'Factory Special' parts by 'Bell & Small' an Edinburgh MC Dealers. It competed in various trials over the years until it was ridden in the 1962 SSDT by Eric MacNamara under No. 190. Eric represented the 'Edinburgh & District motor Club'. This is a Special machine and differs from the 350 'bullet' of the time.
The bike has a BTH 'TT' magneto, with a broken advance/retard cable. The reason the cable broke (I assume) is that the slip ring was seized. I have stripped the contact breaker assembly down.
I have been searching the net for details of this Mag, but haven't found much apart from some pictures of complete units and sites offering Magneto Refurbishment.
The problem I have is that there is a steel plug with a small steel peg that fits through the side of the bronze housing. The peg fits a slot in the slip ring and limits the ring's rotation. The peg is offset and may possibly be rotated to provide fine adjustment to maximum advance or retard. It has been abused by someone in the past and is fixed solid.
I need to remove this plug in order to 'lap' the slip ring into the bronze housing to restore easy, shake-free movement. Heating and tapping with a drift hasn't worked and I don't want to be brutal (yet). This Mag is over 60 years old.
I need an exploded diagram . . before I find the exploded bits in my hand .
Does anyone have details of this 'TT' mag, or a link to such ??
Any clues gratefully received.
Bob.