Re: '78 R100s kill switch fried
Posted: Sun Jul 27, 2025 6:29 pm
With what Rob said and I agree with.... If it were me....
If I read this correctly, with the pivot bolt out, the hole in the frame and the hole in the bearing are not lined up. That is not a problem, at least on my Guzzies. With the bike on it's center stand and the rear wheel just off the ground, you should be able to pull/lift/push the swing arm to align the holes. Then thread in the pivot bolt.
You could have damaged threads in the frame, do your best to look for damage. Before buying a special tap, I would try threading in the pivot bolt. IIRR the threads are a fine thread, easy to cross thread, at least my Guzzi is. So use extreme care and make sure the bolt is going in straight and the holes are aligned. It should go in a bit with your fingers. A Tip...Turn bolt counter clockwise until you feel it just drop in to the threads, then go clockwise gently. Provided the threads are not damaged, you should be able to turn the bolt "VERY VERY" easily with a wrench with just 2 fingers on the wrench. IF NOT STOP!!!!!!!...Unscrew bolt and try again. Fine threads sometimes have two places that it will try to thread in. One will do easy for a half turn or less, the other continues easily. When you find the right one with undamaged threads, it goes right in.
You should also be able to try threading in the bolt backwards, smooth end out. This will allow you to check the bolt in the frame threads with the swing arm in place. BUT.....If in doubt, pull the swing arm, at least back a bit maybe??, so you can test the threads in the frame without having to worry about the bearings causing a cross thread.
Hope this helps a bit,
Tom
If I read this correctly, with the pivot bolt out, the hole in the frame and the hole in the bearing are not lined up. That is not a problem, at least on my Guzzies. With the bike on it's center stand and the rear wheel just off the ground, you should be able to pull/lift/push the swing arm to align the holes. Then thread in the pivot bolt.
You could have damaged threads in the frame, do your best to look for damage. Before buying a special tap, I would try threading in the pivot bolt. IIRR the threads are a fine thread, easy to cross thread, at least my Guzzi is. So use extreme care and make sure the bolt is going in straight and the holes are aligned. It should go in a bit with your fingers. A Tip...Turn bolt counter clockwise until you feel it just drop in to the threads, then go clockwise gently. Provided the threads are not damaged, you should be able to turn the bolt "VERY VERY" easily with a wrench with just 2 fingers on the wrench. IF NOT STOP!!!!!!!...Unscrew bolt and try again. Fine threads sometimes have two places that it will try to thread in. One will do easy for a half turn or less, the other continues easily. When you find the right one with undamaged threads, it goes right in.
You should also be able to try threading in the bolt backwards, smooth end out. This will allow you to check the bolt in the frame threads with the swing arm in place. BUT.....If in doubt, pull the swing arm, at least back a bit maybe??, so you can test the threads in the frame without having to worry about the bearings causing a cross thread.
Hope this helps a bit,
Tom