Ironhead Circuit Breaker 1971 to 1975 Models

Ironhead Circuit Breaker 1971 To 1975 Models See

Ironhead circuit breaker 1971 to models see Ironhead Sportster Circuit Breaker 1971 To 1975 Figure. It shows all the parts this circuit beaker is made of. The numbered part list allows one to learn the correct name of whatever part needs to be replaced. Being able to ask for the right part usually impresses the custom motorcycle shop owner the replacement is purchased from. A picture like this makes it easier to put the circuit breaker back together than just the plain old memory of taking one apart. Why don’t bikers just visualize as parts are put back together?

Ironhead Circuit Breaker 1971 To 1975 Models Is

The Ironhead circuit breaker 1971 to 1975 models is made up of the following parts. Starting on the outside of the gear case cover has a cover. The cover is held in place by two small screws. Then there is a gasket that fits right under the cover. Then there are two breaker plate screws. In late 71 and 72 they hold the retainer in place. that hold the retainer in place. They aren’t exactly the same. The upper one on the right is one piece. The lower one on the left breaks apart. Then dead in the center in the cam bolt. Then the Ironhead Sportster 1971 to 1975 breaker plate assembly sits in place. Then there is a breaker cam that sits on the advance assembly. Why shouldn’t any ignition placed into the side of the engine be advanced and retarded by hand?

Ironhead Circuit Breaker 1971 To 1975 Models Has

The Ironhead Circuit Breaker 1971 to 1975 models has a couple of very important parts. One of them is the advance assembly. It is the  sprung weights that actually advance the timing as the engine rotates faster. The pieces all fit onto the plate that has a long shaft sticking out from the center of it and two tiny shafts in the corners of it. There are two flyweights one over the other. There is a roll pin in each flyweight. There is also a spring hooked up to the narrow end of each flyweight. The advance assembly sits into the engine. It gets covered by the breaker plate assembly. Most of the time the the advance assembly can be taken out of the engine in one piece. That way it is easier to clean and lubricate. Why do weights have to be used to advance the ignition?  

Ironhead Circuit Breaker 1971 To 1975 Models Breaker

The Ironhead circuit breaker 1971 to 1975 models breaker plate assembly sits over the advance assembly. It is a flat breaker plate that has the breaker contact assembly known as points on it. There also are the condenser and a couple small bolts that hold the points and condenser in place. The points have the terminal end wire connected to them. The condenser just gets connected to the points. The two breaker plate screws hold it in place after the ignition timing gets set. Why did the magneto get replaced by such a complicated ignition?

Ironhead Circuit Breaker 1971 To 1975 Models Removal

The Ironhead circuit breaker 1971 to 1975 models removal works this way. Start out by removing the circuit breaker cover and  gasket. Next remove the wire and terminal from breaker contact terminal post. Then remove remove breaker plate after removing screws or retainer. Remove cam bolt. Remove the breaker cam. Pull the centrifugal advance mechanism out by the piece the breaker cam covered. Why does the ignition come in so many pieces?

Ironhead Circuit Breaker 1971 to 1975 Models Inspection

The Ironhead Circuit Breaker 1971 to 1975 models inspection routine works like this. Go ahead and disassemble the circuit breaker and inspect all parts for wear or deterioration. On models so equipped , check advance mechanisms for free operation.Be sure that springs are not stretched or distorted. Be sure that the wire that goes from the circuit breaker to coil is in good condition. Check breaker points for pitting or burning. Replace them in case of doubt. Why doesn’t rusty metal spark as well as shinny clear steel does?

Ironhead Circuit Breaker 1971 To 1975 Models Condenser

The Ironhead circuit breaker 1971 to 1975 models condenser is connected through a wire from it to the points. The condenser is a sealed unit that requires no maintenance.Be sure that both connections are clean and tight. In the event that no test equipment is available a quick test of the Ironhead Sportster circuit breaker 1971 to 1975 condenser can be made by connecting the condenser case to the negative terminal of a 12-volt battery, and the positive lead to the positive battery terminal. Allow the condenser to charge for a few seconds, then quickly disconnect the battery and touch the condenser pigtail to the condenser case. If you observe a spark as the pigtail touches the case, you may assume that the condenser is OK. If the condenser is open, excessive sparking can be noticed when breaker points open. No spark will be observed if the condenser is shorted. Why is it easy to check the condenser without some fancy expensive tool?

Ironhead Circuit Breaker 1971 To 1975 Models Points

If Ironhead circuit breaker 1971 to 1975 models breaker points that are burned should be replaced. If pitting is minor , they may be dressed by a fine point file. Do not not attempt to remove all roughness, it is only necessary to remove dirt or scale. If a few file scrapes do not clean up points replace them. Measure contact pressure with a spring gage, if one is available. Contact pressure should be 14 to 18 ounces. Greater pressure will result in rapid rubbing block wear, less may cause missing at high speeds. Be sure breaker contacts meet squarely. Replace them if they don’t. Always adjust ignition timing after any service operation on breaker points. Why should Ironhead riders have to know how to set the ignition timing on their own instead of taking the custom motorcycle to a repair shop?

Ironhead Circuit Breaker 1971 To 1975 Models Reassembly

The Ironhead circuit breaker 1971 to 1975 models reassembly is an exact reverse of taking it apart. One must stick the advance assembly in first. After this part has be cleaned and inspected it should be lubricated before it gets put back in use. Many of the custom motorcycle riders that still run an old Ironhead Sportster use some WD-40 to get this bit done. One can get the Ironhead Sportster circuit breaker reassembled and leave the breaker points and circuit breaker as the last bit of reassembly. Now it is time to adjust the points and timing. Why shouldn’t one use a magic marker to draw a line in the gear case cover and breaker plate so that can be line back up after reassembly?