[therabbithole]

I've lost 2 tappet caps from vibration. I'm embarrassed to admit that it was two out of the same hole, too, but there it is.

I assumed I'd just left the first one too loose but I used red loctite on the second one and it left too. Now, I'm getting better at leaning up across the tank and checking it while riding.

This doesn't seem safe.

And yes, it still vibrates back out, despite the loctite. I also tried teflon tape (per advice from someone here), to try to take up some extra clearance, but that didn't quite work either.

Short of safety wiring, are there any other options? The threads in the rocker box look okay but I'm assuming they're stretched enough to prevent the cap from fully tightening. Maybe? Has anyone else have any experience with this?

 

[Mr.Pete]

Have you still got the spring clips on the rockerbox to lock into the serrations on the outside diameter of the cap?That should be enough to stop them vibrating loose.

If you have aftermaket caps with no serrations,you will need to fit springs or safety wires.If they are finned,drill 3 or 4 equi-spaced holes around the edge of the top fin.Hook a spring (or wire) between 2 caps,so it tightens both.

 

[Steve69]

a good ployi have used in the past, drill 4 or 8 1/16inch holes around the periphery
of the cap, and then put a tension spring between two caps hooking in into
a pair of apropriate holes.

lockwie is good too, but the springs are much easier attach and remove.

steve

 

[DAVE M]

would O rings help?

 

[therabbithole]

Thanks! I had to go back out and look, since I wasn't sure (embarrassing). The spring clips are still installed but they're all bent upwards and no longer make contact with the caps. I'll start by trying to get them straightened out. I just never thought they'd be enough to overcome however much vibration I assumed must have been needed to loosen the standard caps.

I'll also have to look at what I've got on hand in terms of extra caps. It's a mix of the raised hex-head caps and the original-style flatter, cross-headed caps. I'll try to find a pair of the finned ones since they'll probably be easier to drill.

Ignorant question for you, Dave M: o-ring under the head of the cap to add friction between it and the face of the rocker box? That might help keep them in place? Was that the idea, or am I misunderstanding?

I never had the opportunity to think about dealing with vibration when the bike didn't run enough to have the chance to vibrate...

Thanks again, all.

 

[DAVE M]

yeah, the use of an O ring to reduce the vibes or act as a kind of shakeproof washer was the idea. I've never tried it.

You can get replacement spring clips

 

[therabbithole]

so it's harder to make safety-wire drillings look okay than it might seem, eh? It looks a little sloppy, but I found a pair of the hex-head caps and drilled a single [crooked] hole through one corner of each of the hexes before i wrapped a single wire through both caps.

I'm pretty sure the threads in the rocker box are indeed stretched - the left-hand exhaust rocker cap won't actually torque up when it's fully seated and won't start in too easily.

I'll eventually circle back around and see if I can find a replacement rocker box and then either get new spring clips or straighten the old ones but, for now, at least that's one more pair of fasteners I don't have to check mid-ride!