Just had a stud made to fit inside the crankshaft to hold the rotor on for a Electra the NOC had no stock. I did get the nut from NOC which fits the new stud fine. The new stud was made 16 TPI and 1 1/2 in long but having trouble to get it to enter the crankshaft. The new stud was made with the thread the same on both ends I am thinking maybe the crankshaft as a different thread or needs a tap. Bryon
Electra Crankshaft bolt
Hi Bryon,
The Electra uses a special bolt. 1/2 ins BSF, with a thin head. The head has to be thin so that the bolt head does not touch the starter clutch and pawl assembly.
The bolt on the crankshaft of an Electra has to retain the alternator rotor and the starter drive ratchet gear.
If your Electra is being built without a starter motor and all that goes with it, you may get away with a stud and locknut in place of the proper bolt.
Your crankshaft end will have special dogs to engage with the starter drive ratchet gear. From memory these will not interfere with a standard thick alternator rotor retaining washer.
All lightweight crankshafts are tapped 1/2 BSF at the drive end.
Hope this helps.
Peter
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Electra Crankshaft Bolt
Hi Peter, Thanks for the help I now no for sure it is1/2 BSF. Our local dealer has offered to loan me a tap. I was a bit scared to use brute force on some thing like that. I have been using Bruce Main Smith spares book which calls for a stud and nut maybe the bolt came later. The starter motor is seized up and not sure what else is missing so will not try on using it. Thanks Bryon.
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Electra Crankshaft bolt
Bryon,
Attached is a copy of the illustration I believe you are working with. If you look inside the starter drive ratchet gear you can see the hexagon head of the crankshaft bolt shown. You cannot see the special tab washer that locates in a hole in the ratchet gear and is bent up around the hex bolt side after tightening. Very important in this application where the starter torque tends to loosen the bolt.
Look on the outrigger assembly that is held by three studs to the chaincase inner. You can see a shaft, with circlip and washer, that will be above the hex bolt head on assembly. Very little clearance and explains why the bolt head is exceptionally thin and counterbored (not shown on drawing) to clear the outrigger shaft.
Interestingly, the seal at the rear of the primary chaincase is shown in a plate fixed with four rivets. All Electra used the later gearbox which in turn had a different seal arrangement without fixing plate.
These drawings are not absolute, but they are generally correct.
I hope one day you can get your starter motor working. The Electra is a doddle to start with the kickstart.
Happy lockdown.
Peter
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Electra Rotor Stud
Hi, All good stuff above.
Here are a couple of pictures to assist you. Jubilee & Navigator had a stud, same thread both ends and a nylock nut. The Electra had a bolt with a thin head to allow the starter mechanism to sit over it.
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Hi Bryon - just checked my (late 65) Jubilee so could be the same as the Electra. Stud is as you’ve described (see photo) and screws directly into the Crankshaft so should be 1/2 BSF (16tpi). You might have some old loctite in the threads.
Bruce