I think my camshafts broken ... Please advise

Cpkid

Cpkid

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My 1971 new addition just got ugly. I bought the bike to restore . It didn't run , but it was complete. In going over the bike I noticed problem with the advance Assembly or governor being broken.

Question ...I know the breaker shaft Assembly goes through the cam. The nut on tthe advance Assy. Does it thread onto the cam ? because that nut has a sheared off piece inside it with the keyway that turns the breaker shaft to move the points I believe.

Looks like I need a new cam, at minimum. I'm a little sick about this. I at least wanted to get the engine going. let me know your thoughts. This project just took a nasty turn.

Regards and thanks in advance,

Cpkidq
 
I didn't understand a word you said, lol. Got any pics?
 
So far from your description that doesn't sound very ugly. If the pistons move up and down, that's pretty compared to most of what I've got.
 
no the cam shaft (part 1) is hollow, the cam breaker shaft may be broken tho' (part 6)
 

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Yes it could be the Something on the breaker shaft. It has a key that the breaker shaft pin goes in, there are threads on the broken piece. I don't know how to attach a picture yet. From my book it could be what's called a (cam) but it's attached to the breaker shaft.
 
Cpkid, I think I know what you're trying to describe. When the nut that secures the automatic timing unit (ATU) to the camshaft loosens, the pin that aligns the ATU with the camshaft during assembly slams into the sides of the alignment slot in the ATU body, deforming and sometimes breaking it. Good reproduction timing units are available from Mike's XS at a very reasonable price. Check your pistons; one of them may have a hole in it, as that often happens when the ATU goes haywire.
 
That piece in the middle does not belong in the middle of that nut. That outside piece threads onto your camshaft and the piece in the middle goes to your atu weights witch connects to your cam rod
 
Nope stock but again that piece in the middle has those little cut outs for those weights (the things that are on the springs) that's where it belongs
 
Right. Cpkid, pay attention. The assembly in your hand is the complete ATU. Fit the timing rod (item with points cam on the end) through the camshaft, and fit its pin into it. Make sure that the pin is on the same side of the rod as the points cam key way. At around 1:00 in your photo, note the line scribed in the ATU rotor, right next to the spring post. In the middle of your photo is the timing disc. It has a line scribed on one side; install the disc with the marked side facing out, align the line with the line on the rotor, and fit the tips of the bobweights into the notches in the disc. Fit the ATU onto the end of the camshaft and tighten down the ring nut, keeping the slot in the rotor aligned with the pin in the camshaft, and keeping the pin in the timing rod aligned with the slot in the center of the timing disc. Finish tightening the ring nut with a flat punch and BFH, and don't be gentle about it; if the nut comes unglued while the bike is underway, catastrophic failure can result. Blue Loctite doesn't do a bit of harm there.
 
I think I get it now. The cam shaft threads are poor , and I'm missing the pin that goes into the camshaft . I have the one for the breaker shaft. I can't imagine the history of how everything got bent up. I'll reassemble and hope for the best when I get more parts.
 
If the threads on the camshaft are in poor condition, you'd better change your plan. If the ring nut comes unglued, ignition timing under power goes way to the advanced side, and if the engine isn't shut down in a hurry, this very often results in a holed piston. Used camshafts aren't hard to come by; you need one with 34 teeth on the sprocket ('70-'73). You can also use an electronic ignition that does away with the ATU from either Probe Engineering (superior design, construction, and features) or Boyer (poor design and construction, but very resistant to interference). They're around the same price--about $300. The Boyer comes with a dual-tower coil and one has to be bought for the Probe, but the Gill coil supplied with the Boyer should be thrown away and replaced from the git-go.
 
First of all thanks for all the advice !
I read all your replys and did exactly as suggested . I never heard of a thread restorer . But I got one and they work great. Here's what I did.
Bought a new advance assembly from Mikes
Changed the oil
Adjusted the valves
Gapped and replaced spark plugs ( had to replace a failed helicoil )
Adjusted the points
Cleaned carbs ( will rebuild next )
Cleaned carb pods
While restoring threads on advance assembly I looked down under plug and saw the missing cam dowel. Game on then.
Assembled advance assembly put in fresh high test gas and and carb cleaning additive.
She started up rather quick and runs strong. Idle is good and you can tell compression is high.
I now will spend more $ because old yeller is back from the dead.

Thanks again for all who helped. And reading other posts I've learned a great deal.
 

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