Tappet safety wire strategy

Hi all,

Onto the next thing in my MKIII rebuild, securing the tappet screws. There is info and diagrams on the web for how its done for aviation, orienting the wire to pull each screw tight against the other etc. But the available space around these screws is so small that I am really struggling to keep everything tight as I twist the wire! I'm using the same gauge wire that came out of the bike, which is .038" stainless steel. And the orientation of the fully seated screws is a little funky, requiring twists to happen between the screw and the barrel casting, which is maybe 1" of space. Does anyone have a successful strategy for keeping things tight in the space available? The original wire was tight so I know it can be done somehow.

Alternatively, if I put a little blue thread lock on the screws and get the wire in albeit imperfectly tight, would that be sufficient? How would you guys do it on your bikes? I have plenty of wire to keep trying but my results have all been pretty similar...

Thanks,
Anthony

Anvill said:

Alternatively, if I put a little blue thread lock on the screws and get the wire in albeit imperfectly tight, would that be sufficient?

Click to expand...

Quite sufficient !

Safety wire, have never used it on my Norton in 48+ years of ownership, never had a problem with things coming loose even with my Commando motor hard mounted in the Featherbed frame, Loctite on things that needs it only, other than that good spring washers work good with find threads or any bolts for that matter.

I would never use safety wire here - just avoid using those crappy aluminium nuts.
Good torque on steel nuts is more than enough IMHO!
Cheers

Edit: Sorry, just twigged that you probably mean the four screws that hold the tappet/cam followers in their bores. Still, Loctite Blue (243) will be more than adequate - well that's what I would do, anyway.

I

Anvill said:

Hi all,

Onto the next thing in my MKIII rebuild, securing the tappet screws. There is info and diagrams on the web for how its done for aviation, orienting the wire to pull each screw tight against the other etc. But the available space around these screws is so small that I am really struggling to keep everything tight as I twist the wire! I'm using the same gauge wire that came out of the bike, which is .038" stainless steel. And the orientation of the fully seated screws is a little funky, requiring twists to happen between the screw and the barrel casting, which is maybe 1" of space. Does anyone have a successful strategy for keeping things tight in the space available? The original wire was tight so I know it can be done somehow.

Alternatively, if I put a little blue thread lock on the screws and get the wire in albeit imperfectly tight, would that be sufficient? How would you guys do it on your bikes? I have plenty of wire to keep trying but my results have all been pretty similar...

Thanks,
Anthony

Click to expand...

It's ok, doesn't need to be perfect.

concours said:

I

It's ok, doesn't need to be perfect.

Click to expand...

Some people just get carried away with this shit…

Anvill said:

Hi all,

Onto the next thing in my MKIII rebuild, securing the tappet screws. There is info and diagrams on the web for how its done for aviation, orienting the wire to pull each screw tight against the other etc. But the available space around these screws is so small that I am really struggling to keep everything tight as I twist the wire! I'm using the same gauge wire that came out of the bike, which is .038" stainless steel. And the orientation of the fully seated screws is a little funky, requiring twists to happen between the screw and the barrel casting, which is maybe 1" of space. Does anyone have a successful strategy for keeping things tight in the space available? The original wire was tight so I know it can be done somehow.

Alternatively, if I put a little blue thread lock on the screws and get the wire in albeit imperfectly tight, would that be sufficient? How would you guys do it on your bikes? I have plenty of wire to keep trying but my results have all been pretty similar...

Thanks,
Anthony

Click to expand...

I had the same thoughts when faced with this task. If I remember,these are cheesehead screws which can be challenging to tighten. If one comes loose and works it's way out, it could be an expensive repair. The factory lockwired them so I did too, it took a few tries to get it right, blue locktite, and for me well worth the time for peace of mind since it may be a long while till they are seen again.

I forgot to do it a couple of builds back and remembered just before putting the engine back in the frame. Took the engine apart to do it cuz I thought I'd lost my mind and wanted to see if it was in there somewhere.

As concourse mentioned it does not have to be perfect and I'll add or show quality. Do it with everything very clean, no oil residue on the threads in the barrels or on the goofy little cheesehead screws use the blue loctite and give the safety wire your best effort. Let it dry 24 hours before assembly. Those screws aren't going anywhere with blue locite and wire running through them.

Anvill said:

Hi all,

Onto the next thing in my MKIII rebuild, securing the tappet screws. There is info and diagrams on the web for how its done for aviation, orienting the wire to pull each screw tight against the other etc. But the available space around these screws is so small that I am really struggling to keep everything tight as I twist the wire! I'm using the same gauge wire that came out of the bike, which is .038" stainless steel. And the orientation of the fully seated screws is a little funky, requiring twists to happen between the screw and the barrel casting, which is maybe 1" of space. Does anyone have a successful strategy for keeping things tight in the space available? The original wire was tight so I know it can be done somehow.

Alternatively, if I put a little blue thread lock on the screws and get the wire in albeit imperfectly tight, would that be sufficient? How would you guys do it on your bikes? I have plenty of wire to keep trying but my results have all been pretty similar...

Thanks,
Anthony

Click to expand...

It's only important that the don't come out. I use Blue, get them tight, and put the safety wire in but don't go crazy getting it tight. If you twist too much you can weaken the wire and make it worse than useless!

I try each screw in each hole and find the best one for each. I would love them to be in a line on each side. Second best is close to vertical. Either of those make the safety wiring easier to do.

Fast Eddie said:

Some people just get carried away with this shit…

View attachment 115720 View attachment 115721 View attachment 115722

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Uh, It seems Boeing sure doesn't

Tighten the two screws till they are bottomed out. Then back them off just enough to align the holes to pass the safety wire through the holes of each. Now Re-tighten the two screws tight. Bring the tail ends of the two wires together in contact, attach the safety wire pliers to clamp these ends and twist them tight. the tails should be approximately 1 to 1 1/2" in length after twisting. It should be a nice tight twist in appearance. Cut just enough off after a tuck under one of the two screw heads to keep it out of the way. Discard the excess. Job done!
Lock wire is old tech but works with vibration. That's why they used it. It is a good visual marker to know that things won't come undone.
Loctite technology has come along way to do the same. 243 is OK to use in an oil saturated environment. I use 242 on anything outside the bikes internal "whirly bits".
I still use Safety wire in this application of the tappet retainers. Racing scrutineers want to see safety wired bits when they evaluate your bike before race day. Aircraft still use this for good reason.
YMMV.

As you say, there isn't enough room to do a 'proper' job.
I took the view that as long as the wire crosses over between the screws it's all good. The originals I've seen weren't exactly 'textbook' either.
I'd never thought about lining the screws up for threading the wire before tightening - definitely stealing this idea for the next one

One of the most satisfiying jobs on an old Norton. But you need safety wire pliers.

elefantrider said:

One of the most satisfiying jobs on an old Norton. But you need safety wire pliers.

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Mac Carr, harbour freight, princess auto, Grainger, Aircraft Spruce... Any good tool supply shop would carry these.
Even Amazon carries them. The Chyna Nockoffs are cheep.
budget accordingly.

Perhaps I went a bit over the top with the loc wire. But after I had a float bowl come loose at the top of a 5600' pass in the cold rain soaking my leg with gasoline, I thought maybe I should loc wire the float bowl screws. So I locwired all the carb screws. None has ever come loose since.

We were pushing it hard. That was the day DynoDave passed the cop at over the ton (DOD nominal) in that spot. Cop had stopped to render assistance. Dyno was a bit behind us and hurrying to catch up. He just kept going. That story has been told over many, many beers.

Its funny how everyone calls things differently when I first read this thread when it came on safety wire tappets, I though W T F as to me tappets are at the top of push rods and lifters are at the bottom, when I reground my lifters I loctite the screws and safety wire as stock, the only place I ever used safety wire.
As for carb screws the only reason they come lose is been done that many times the little spring washers have lost the spring to hold them in place, I have a big stock of spring washers in my shed from very small to large and have never lost a carb screw yet in 48+ years, lost a idle/air screw but that was worn O rings, but its all part of maintenance is to go over everything to make sure they are tight and replacing slotted screws with allen head screws is a good idea and good spring washers should be good enough to hold screws, nuts and all.

Ashley

CanukNortonNut said:

Mac Carr, harbour freight, princess auto, Grainger, Aircraft Spruce... Any good tool supply shop would carry these.
Even Amazon carries them. The Chyna Nockoffs are cheep.
budget accordingly.

Click to expand...

If you are comfortable with having harbour freight tools in your toolbox, on sale now at $6.99. I am not, so mine are Stahlwille.
Proto, Bluepoint, Milbar are good alternatives.

Ashley quote:
"As for carb screws the only reason they come lose is been done that many times the little spring washers have lost the spring to hold them in place,"
Or as we get old and sight challenged, forget or not paying attention to one of those silly washers like me. Murphy's law always creeps in.
Little things are important. They are there for a reason.