Points Caps with Cut Outs
As originally manufactured, most magnetos designed for single cylinder engines do not have a facility for an ignition cut out. That has now changed! Following numerous enquiries from our customers over the years, The Magneto Guys have now developed neat, reliable points cap cut outs for a range of magnetos as follows:
Please note: Points caps 3, 4 and 5 all incorporate a carbon brush which makes contact with the bolt used to hold the rotary points. It is important to ensure that the head of this bolt is smooth and preferably slightly domed. We occasionally see bolts which have been modified with a screwdriver slot - these will need to be changed to a standard bolt if these caps are to be fitted.
My bike has not had an ignition cut out for the last 40-50 years - why do I need one now?
There are several good reasons worth considering:
Use it to stop the engine safely: it’s true that the engine can be stopped by using the valve lifter. However, at higher revs there is a risk of causing damage to the valve lifter and/or the valve mechanism itself. Run the cut out wire to a handlebar mounted push button switch.
(Switch not included)
Use it to comply with racing regulations: an ignition cut out is a mandatory requirement in most forms of motorcycle sport and competition. Run the cut out wire to a handlebar mounted lanyard operated switch.
(Switch not included)
Use it as a security device:
most machines fitted with these magnetos had no security measures fitted as standard. Run the cut out wire to a hidden switch or perhaps a key operated ignition switch.
(Switch not included)
Use it as a safety device:
do you like to use an on/off tap in the oil line to prevent wet sumping? Run the cut out wire to a modified oil tap fitted with electrical contact points. It will prevent the engine being started without remembering to turn on the oil tap first.
(Switch/oil tap not included).
The push button, lanyard key and ignition switches are all standard parts readily available from a number of suppliers so The Magneto Guys do not supply these. However.....
The Magneto Guys can now supply an Oil Tap with Cut Out Switch
in a range of types and sizes!
Whichever type of switch is used, it is important to remember that when the switch is 'open' the magneto will work normally and when the switch is 'closed', the magneto is shorted to earth and the engine stops.
HOW TO BUY: All these points cap cut outs can be purchased direct from us, the designers and manufacturers. A full invoice will be included with all purchases. Payment can be taken using PayPal by clicking on the relevant Buy Now
button below.
Overseas sales always welcome! Please check IMPORTANT NOTES FOR OVERSEAS CUSTOMERS

1: For Lucas face cam magnetos including MO1 and N1 models
The points cap cut out uses a new metal points cap* modified to carry an insulated stainless steel stud which, in turn, houses a spring loaded carbon brush. The stud carries a ring terminal with approximately six feet of wire. The stud and electrical connection is then covered in a plastic cap with the whole arrangement held in place by a lengthened stainless steel points cap clip. Three types of points cap clip are available. For MO1 magdynos, if the clip is fitted in the top left hand corner (as in the picture), choose the short MO1 clip. The long MO1 clip is fitted in the top right hand corner. The third type of clip is designed for the N1 range of magnetos.
*PLEASE NOTE: We manufacture all the parts for the metal cap version ourselves with the exception of the points cap. Initially, we used either aluminium alloy or chrome plated steel depending on what was available from our suppliers at the time. We then found a good reliable supplier of stainless steel caps and now we always use these. However, if you have an 'oily rag' bike, just let us know and we will look for a matching cap - or send us your cap and we'll use that!
IMPORTANT:
Please make sure that there is sufficient room for the increased depth of this modification - on some machines the magneto points cap is very close to the inside edge of the primary chain case. The plastic cap is 22mm in diameter and the depth of the plastic cap and clip is 18mm. To keep the increased depth to a minimum, our new clips do not have the curled end as seen on the originals. This picture shows an original clip resting on top of our new one to illustrate the differences.
METAL cap cut out for Lucas MO1 and N1 face cam magnetos:
ONLY £53.00 incl. P&P to anywhere inside
the UK!
For UK Sales only:
Click this button to buy metal cap cut out
with LONG MO1
clip
For
UK Sales only:
Click this button to buy metal cap cut out
with SHORT MO1
clip
For UK Sales
only: Click this button to buy metal cap cut out
with N1
clip
ONLY £59.00 incl. P&P to anywhere outside the UK!
For Overseas Sales only: Click this button to buy metal cap cut out
with LONG MO1 clip
For Overseas Sales only: Click this button to buy metal cap cut out
with SHORT MO1 clip
For Overseas Sales only: Click this button to buy metal cap cut out
with N1 clip
2: For Lucas face cam magnetos including MO1 and N1 models
Also for some ML face cam magnetos including CMA and CMAK types
This points cap cut out also uses a new cap, this time made in black nylon but this version uses the original clip. The cap is fitted with a brass sleeve which houses a carbon brush and spring. The cap comes ready fitted with approximately six feet of wire. This version of the points cap cut out is suitable for both types of Lucas MO1 and Lucas N1 magnetos, It will also fit some types of ML magnetos which use face cam points including CMA and CMAK types.
NYLON cap cut out for Lucas MO1 and N1 and ML CMA and CMAK magnetos:
ONLY £43.00 incl. P&P to anywhere inside the UK!
For UK Sales only: Click this button to buy nylon points cap cut out
ONLY £49.00 incl. P&P to anywhere outside the UK!
or Overseas Sales only: Click this button to buy nylon points cap cut out
3: For BTH magnetos using three bolt fixing for the points cap
This points cap cut out uses a new black nylon cap. The cap is fitted with a brass sleeve which houses a carbon brush and spring. This version of the points cap cut out is suitable for BTH BKH1, TT, Dirt Track, KC1 - basically, all types which use the 'competition' type of cap held in place with three small bolts.
Cut out points cap for BTH 'three bolt' type magnetos:
ONLY £37.00 incl. P&P to anywhere inside the UK!
For UK Sales only: Click this button to buy BTH 'three bolt' type points cap cut out
ONLY £43.00 incl. P&P to anywhere outside the UK!
For
Overseas Sales only: Click this button to buy BTH 'three bolt' type points cap cut out
4: For BTH magnetos using clip fixing for the points cap
This points cap cut out uses a new black nylon cap. It holds a beryllium copper spring strip fitted with a brass cup housing a thin carbon disc which makes contact with the points holding bolt. This version of the points cap cut out is suitable for BTH KC1, KD1 - basically all types which use a clip to hold the cap in place including magnetos fitted to some later models of Rudge motorcycles. The cap is designed to be used with the original clip but because the cap is slightly thicker than the original, a new spacer (included) needs to be fitted under the original clip.
Cut out points cap for BTH 'clip' type magnetos:
ONLY £45.00 incl. P&P to anywhere
inside the UK!
For UK Sales only: Click this button to buy BTH 'clip' type points cap cut out
ONLY £51.00 incl. P&P to anywhere outside the UK!
For Overseas Sales only: Click this button to buy BTH 'clip' type points cap cut out
5: For Lucas K2F magnetos using domed cap with push button cut out
This points cap cut out uses a new black nylon cap. It is designed to replace the original Lucas cap part no 459037 which incorporate a push button cut out often found on AJS, BSA and Matchless twins, possibly others too. The cap is fitted with a brass sleeve which houses a carbon brush and spring. The cap is held in place with the original pair of studs/nuts.
Cut out points cap for Lucas AJS/BSA type magnetos:
ONLY £39.00 incl. P&P to anywhere inside
the UK!
For UK Sales only: Click this button to buy Lucas AJS/BSA type points cap cut out
ONLY £45.00 incl. P&P to anywhere outside the UK!
For Overseas Sales only: Click this button to buy Lucas AJS/BSA type points cap cut out
Overseas sales always welcome! Please check IMPORTANT NOTES FOR OVERSEAS CUSTOMERS