Sheared Key 1973 CB450

1057 Views 9 Replies 3 Participants Last post by 66Sprint, Jun 29, 2009

jacob.vanorder

Discussion Starter · May 10, 2009

Yesterday, I pulled a bonehead move with the best of intentions. I wanted to replace the screws which hold in my points from flatheads to allen screws. Unfortunately, the new screws were slightly too long and unbeknown to me, the new screws grabbed onto the points advancer and trouble ensued. The points advancer sheared the key that keeps the point advancer in sync with that cam.

Rut roh.

I was able to take everything apart and get the nub of the key out and replace with a new one but the problem is that there is a little bit of wiggle now. My questions are if this wiggle is going to make it impossible to set my timing correctly and if so, what's the name of that cam specifically in case I have to replace it, I know the correct name.

Thanks in advance!

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jacob.vanorder

Discussion Starter · #4 · May 11, 2009

66Sprint said:
That would be the exhaust cam.... However, I have in the past fixed a situation like yours by replacing the solid metric pin with a short SAE roll pin...Between the slight size (diameter) difference and the "spring" in the roll pin, it will stay in position and still fits the slot in the underside of the advance unit......

If I just go to a motorcycle shop and ask for a short SAE roll pin, will they know what I'm talking about?

I appreciate the advice, though...

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jacob.vanorder

Discussion Starter · #5 · May 11, 2009

tbpmusic said:
Or you could just ask someone here for the pin off a wrecked exhaust cam..........

That's if it comes out - I honestly can't answer that, don't think I ever tried it...

All I know is the mashed one was plenty hard to get out...

Thanks for the reply!

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jacob.vanorder

Discussion Starter · #7 · May 11, 2009

66Sprint said:
No... take the pin you have out...Take it to a hardware store...... Ask for a roll pin with a similar diameter...You'll have to cut it short yourself (it's spring hardened steel, so a cut-off wheel in a Dremel is the best tool....) There is a chamfer on the end of the roll pins (a slight taper)...This will make it easy to get it started into the "pocket"... Cut to length, hold with needlenose pliers, and tap it in....

IF (and it's a big IF) I get near the hardware store in the next few days, I'll get the size specs on the roll pin I've used......

Thanks! I fabricated one by cutting a small screwdriver that was ruined. I did cut it with a dremel and grind it down to the correct length. Getting a tapered one isn't a bad idea, though. I'll see what I can drum up.

Thanks for the idea!

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jacob.vanorder

Discussion Starter · #9 · Jun 28, 2009

66Sprint said:
It isn't the fact that there is a taper on it that makes this work....It is that it is a spring (tube) that can slightly reduce in size (diameter) when forced into a slightly undersize hole....The spring pressure then retains it.....I have always called them "roll pins", but they are also known as "spring pins".....

Ding ding ding! Seriously the best suggestion. I got around to finding a tension pin (1/8" for those of you that have this problem...) and putting it it. It worked great! No wiggle in the spark advance unit. Worked great...

Thanks for the suggestion. If I lived near you, I'd buy you a beer fer sure.

Thanks again!

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