1928 JD engine knock?

[SteveAdventure]

I recently bought a 1928 JD that has had a complete restoration including the engine in the last 3,000 miles. I took it to breakfast on Sunday and a short time after I started onto the highway the bike sputtered to running on one cylinder and died. The points were not opening so I adjusted them and adjusted the exhaust valves which were very tight; maybe no clearance! Both the exhaust valves were adjusted to the loose side at .010. It appears that I have 61” exhaust lifter pins are 2-3/8” rather than the longer pins a 74 should have. Mark Masa said this wasn’t a problem it just takes more time to adjust the valves. The engine now sounds like it has a knock, not at idle but when under a load. What could it be? Thanks, Steve

[MMasa]

Steve
I never said that it wasn't a problem and we discussed a way to swap out the pins without removing the engine from the chassis. If the hex on the lifter pin is bottoming out onto the top of the guide, that's a problem. Also, your adjusting bolts are 1/4" more extended than they have to be.
Your knock could be lots of things.
You said that the motor has had a "complete restoration". My personal philosophy is that if I didn't do it myself or at least supervise the work, it never took place.
If you plan on riding that across the country on the cannonball, it should probably be gone over.
Mark Masa

[SteveAdventure]

My apologies for mis-interpriting your comment! I have the pins ordered and will get them installed. Thanks, Steve

[MMasa]

If you got the pins from Competition, you may have some problems. I've had calls from several people who say that the pins they got were oversized on the diameter and wouldn't fit their stock guides. Anyone else have this problem? I don't know if they make a stock size and an oversize version. You may have to ream the guides.
Don't get me wrong. Nothing against CD. They have made it possible for many a JD to get back on the road. It's just That I've gotten lots of calls on the subject.
Mark Masa

[SteveAdventure]

We pulled the engine and found the aluminum front piston was toast. I’m guessing that the piston skirt was what we heard knocking. It left aluminum residue in the cylinder that will be removed with murattic acid. The piston rods need a little tweaking to straighten. The exhaust pins in the bike were the shorter 61 ci so we’ll get those replaced.