AJS & Matchless Owners Club

Hi Everybody! This is my first new topic, its not very important but some information would be helpful.

I bought a 1961 Model 8 last November. I'm very pleased with how it goes but one thing is getting on my nerves. Over a decade ago, one of the previous owners completely removed the whole valve lifter mechanism, from rocker box to handlebars, leaving just a hole in the rocker box and no other trace of the mechanism, as far as I've been able to tell so far. (I have not yet taken the tank off for a closer look). So there's no lifter, no return spring, no cable, no handlebar lever, not even a nut or washer left.

The most recent owner before me understandably thought it was a bad idea to just leave a significant hole there and screwed a bolt into the hole. They also drilled a small hole through this bolt to act as an extra breather. I am puzzled about what they screwed the bolt into. Should the hole left in the rocker box be threaded? If so, should there be some sort of threaded sleeve (that is not shown on the parts list) in the rocker box and screwed into this hole to accommodate/support the valve lifter?

As a Spring/Summer project, I would like to reinstate the valve lifter, as long as I can obtain parts and its not too difficult or expensive. I can start the engine adequately without it but I feel that it mattered enough to AMC to fit one, so the bike should have one and someone deciding to strip the mechanism out and chuck it away rubs me up the wrong way.

Any information would be welcome. Thanks,

Bill.

Plenty happened to them when they were simply old bikes rather than classic historic bikes. The hole for the valve lifter would have no thread and no insert. It may be the bolt is just pushed in.

I expect you're right about the days when nobody appreciated them. Who knows what might have happened? Thanks for the information, I suppose I'll find out about the bolt when I take a closer look (when the snow has gone and my north-facing garage is a bit more comfortable. Hopefully I'll find that the hole is undamaged!

Thanks,

Bill.

I just replaced the O-ring and spring on mine, as it was loose. As stated in a previous reply, there are no threads. The spring holds the arm in place. When engaged the exhaust valve is opened until the hand lever is released.

Brian

Thanks Brian, I haven't got around to looking at it properly yet but I suspect I might find that the earlier owner, the one who vandalized the thing in the first place, has cut a thread into the hole for some reason and it will mean a new rocker box, if I decide to go through with it. I'll find out in due course.

Sorry, I feel the need to rant about this again, so this post is for no purpose other than venting my frustration . I'm at the beginning of stripping down the rocker box and cylinder head to investigate a sudden loss of compression. I removed the bolt mentioned in my first post in this thread and there is indeed a thread cut into the rocker box. I don't understand why anybody would do this. Words fail me. I know it was not the previous owner but someone before him. I haven't got it off the cylinder head yet so the depth of the damage is unknown but it took several turns to unscrew the bolt, which my vernier calipers tell me is about 0.576" in diameter. I am hoping that they haven't drilled all the way through and that I may be able to salvage something, short of trying to find a replacement rocker box, they are like hen's teeth. I've also found that there is no rotation on the push rods when the engine is stone cold, so I am hoping there is no valve damage. If anybody knows what the diameters of the inner and outer parts of the hole that houses the valve lifter should be, I would really like to know!

Regards,

Bill.

I may not have understood the issue correctly as L/Ws aren't familiar to me but if another rocker box really is unobtainable I would bore out the rocker box casting and fit an (interference fit/Loctited) insert with an i.d. to suit the lifter arm shaft.
According to the parts lists the lifter for the L/W is the same as for the H/W singles - 013969.

Thanks Spriddler, I had in mind something like that as a possibility although it wouldn't be my preferred option because I won't be able to do it myself. I'll have to inspect the rocker box closely when I take it off in the next day or two, then decide whether it will be worth doing or not. In the meantime, I will still keep looking out for a rocker box that hasn't been messed about like mine.

I suppose another possibility might be to have the right-sized hole drilled into a rocker box from a lightweight 250 but it would need to be done exactly and I have neither the tools nor the skill to do that. It would also need to have a hole drilled and tapped to accommodate the screw that holds the return spring in place.

Bill, I have a spare L/wt rocker box without a valve lifter if you want it, then if your rocker box is damaged beyond repair all is not lost. It has the bosses for a valve lifter, and any competent machine shop should be able to drill it. PM me if it's any help. Andy