Seating Pushrod Tubes

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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Re: Seating Pushrod Tubes

Postby SPRIDDLER » Mon Feb 11, 2019 8:46 pm

Iron Head wrote:I was sitting in traffic on Saturday and the old girl was being filmed by a couple in an Italian restaurant both waving enthusiastically - felt very proud of an all original ‘roadworn’ bike that was likely last on the roads in the 60’s!

I know that satisfied feeling: Whilst stopped in Normandy on my '54 civvy G3LS a 'young' chap said his Dad rode one in WW2 and asked me to follow him to his house in a narrow backstreet. He went indoors into a gloomy front room and I heard him tell his Dad he had something to show him. "I know" he wheezed "I can hear it, it's a Matchless". He wheeled the very old boy out into the street and his beaming face was a picture. I offered him a trip round the block even though he was far too weak to do it.

To keep the tubes down, if need be, I have a cunning plan that will involve cutting tight-fitting ‘O’ rings which I will stretch around the top ‘necked’ end of the tubes and then join them again with super glue thereby wedging the tubes downward.

You *shouldn't* be able to do that (as I guess you've realised) as the top shoulder would normally be inaccessible just inside the head. (Ignore the 'O' rings in the other tube hole - I use several of them at the top instead of the rubber sleeve).
BTW - if I was going to do a running fix (bodge) I'd move the tubes as far down as I could and tighten a cable tie around the top of the tube - maybe with some Evostik or a band of cycle inner tube or similar to help the cable tie grip the tube. I might even try with a Jubilee clip instead of the cable tie but really I'd take the head off and do it correctly ;)

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Re: Seating Pushrod Tubes

Postby Iron Head » Mon Feb 11, 2019 10:13 pm

That’s a touching story Spriddler and thanks for your suggestions which are excellent I’ll have a tinker this weekend.

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Re: Seating Pushrod Tubes

Postby Mick D » Tue Feb 12, 2019 7:36 am

Hi

If you can pull the tubes down far enough to reveal the upper waisted portion this would suggest your tubes are too short / incorrect for your engine.

Repeatedly pulling them down will slacken things off increasing the amount of oil leaked and the rate of the tubes moving - how long can you put up with this?

I'd fix it properly now while the weather's not too good.

Regards Mick

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Re: Seating Pushrod Tubes

Postby Iron Head » Mon Feb 18, 2019 10:21 am

I will definitely need to pull the head and fix this properly, and I have discovered that the tubes do want to keep ‘rising’’ during running, assume as a counter-action to the firing stroke?

However here is my ‘temporary’ fix that seems to work well. Stainless spring pipe clips saved from the autopsy I carried out (to my heating engineers amusement) on my old Gloworm boiler. They clip round the pushrod tubes and lock under the fins and also locate into the head gasket join. Bit weird but I can live with ‘em for now!

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Re: Seating Pushrod Tubes

Postby clive » Mon Feb 18, 2019 11:33 am

Smart. The sort of temporary fix that waits for some time before its dealt with.
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Re: Seating Pushrod Tubes

Postby clive » Mon Feb 18, 2019 11:41 am

Iron Head wrote:.......I have discovered that the tubes do want to keep ‘rising’’ during running, assume as a counter-action to the firing stroke?
Iron Head


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