Collets and .... collets

[AyJayBee]

I have finally got round to starting to rebuild a 1961G80, bought as a project about 15 years ago. I stripped the bike and stored items 'safely', but the ravages of time and other distractions - including other bikes - are taxing my memory … 'now where did I put ….' or 'did that go that way round?' The latest stumbling block found me trying to rebuild the head - I know, hairspring valves can be a swine to fit, but this took the biscuit ….. having ground in the valves, I started to fit the inlet. I have one of the semi circular spring compressors which was duly fitted and I dropped in the first collet, followed by the second …. bit of a fiddle, but when I released the pressure on the springs the collets would not fall into place. Several hours - yes, HOURS! - found me still struggling with the first valve, until my son returned from work. He came to see how I was getting on, and his keener eyesight spotted a slight problem - the two collets were different profiles, and would not fit together. On checking I found there were 2 different pairs, one for the inlet and one for the exhaust, as the valve stems were different sizes …. Is that normal? Having matched the collets to the collars - also different! - twenty minutes later found everything sorted, well for the moment anyway, but watch this space! Tony.

[Rob Harknett]

not got a 61 bike, but never found differences as you have found, on bikes I have got .

[1608]

As long as each valve stem is the correct fit in its guide ( don't confuse the i/l with exh valve) thats all that matters. The wasted bit of the v/stem may vary slightly for each set of collets.

[SPRIDDLER]

The wasted bit of the v/stem may vary slightly for each set of collets.

Agreed. And perhaps after all these years it may have received a universal pattern valve (and collets) which will not necessarily be the same design as an AMC factory valve.

[ajsph]

in 1960 the 500 single got a new type of exhaust valve (026029) and collets
Poul

[AyJayBee]

Thanks for your responses - there is a noticeable difference between the assembled collets to suit presumably the valve stem diameter. a 'pair' made up from the two different sets would not locate in the stem recess. But at least the problem was sorted