Pulling the inner plate from a Boyer ignition

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Joe Schlaberdowski

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What is the thread diameter and pitch on the inner plate on a Boyer ignition. The plate with the two little posts to activate the magnetic sensors. I need to use (make) a slide hammer out of a long bolt to get it out (I think). I could just go to a store and get an assortment and try them. Also assuming they're not Whitworth?
 
Usually you can just put like a 6" rod in the bolt hole and gently wiggle it out.
 
It's 5/16" UNF.

To remove, screw a suitable 5/16" UNF bolt into the Boyer rotor few turns then tap the bolt head in different directions.
 
Went to the local all-in-one big box store and (after reading a bit) bought a long 5/16 - 24 x 3 bolt, sae. 5/16 SAE being(as I was told) the same as 5/16 UNF. I can tell it's 5/16, but the threads do not match. Starts to thread in about 1/3 of a turn, then binds up. The threads I can see do look like fine thread, but it's a no go.
 
Joe Schlaberdowski said:
Went to the local all-in-one big box store and (after reading a bit) bought a long 5/16 - 24 x 3 bolt, sae. 5/16 SAE being(as I was told) the same as 5/16 UNF. I can tell it's 5/16, but the threads do not match. Starts to thread in about 1/3 of a turn, then binds up. The threads I can see do look like fine thread, but it's a no go.
Click to expand...

Boyer rotors are threaded 5/16" x 24 (UNF) so if that doesn't fit then someone has probably screwed in the wrong bolt and damaged the thread.
 
Pulling the inner plate from a Boyer ignition



Pulling the inner plate from a Boyer ignition
 
L.A.B. said:
Boyer rotors are threaded 5/16" x 24 (UNF) so if that doesn't fit then someone has probably screwed in the wrong bolt and damaged the thread.
Click to expand...
Looking closely I don't see obvious thread damage (doesn't mean there isn't any of course). BTW, what does the "x 3" indicate? Could that be the difference? Feel like I'm clutching at straws here. I don't want to force it more than I have. Put pressure on it with a wrench and there was just resistance. No turning with pressure. Perhaps I could run a tap in (5/16 - 24X3) ?
 
You are right. Not thinking -- just clutching at straws and typing away. Unless there is a reason not to, I'm going to run a tap in. Thanks.
 
5/16 bolts/screws are usually available as 5/16-18 and 5/16-24. Most times the fine thread versions of a lot of bolts/screws are harder to find. Someone probably sold you a 5/16-18. Ace hardware has a pretty good selection.
 
Or, borrow an existing 5/16" UNF from the bike.
 
I ran a die over the brad new Chinese 5/16 z - 24 bolt and it was tight (not so good with toleranxes there). Tap and die set made by Irwin - USA. Then ran a tap in the end of the inner plate of the Boyer. It was pretty bad. A bit of metal came off. Put the bolt in and the plate came off nicely just by turning the bolt in a little. But when it came off I noticed bits of metal in the hole at the end of the cam. I don't want to leave that there. If that's a blind hole I thought I could insert the thin red plastic tube of a spray can of brake clean carefully down the middle of the hole to the end -- and then blast out the metal bits. IF that's a blind hole.
 
Of course it's obvious, but the "z" in 5/16 z 24 shouldn't be there. Also decided to use pipe cleaners coated with a little grease to pick up metal slivers. Insert down the middle and then roll around and carefully take out. A couple of pipe cleaners worth ought to do it. Noticed there was nothing much at all beyond the opening at the end of the cam. Well, I guess this was all much to do about nothing. But it helps to pass the time.
 
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