Rocker Spindle Shims

I would also check that the shafts locate with the outer plates and are not free to revolve,may be necessary to pack the shafts or fit the RGM repair kit.

Previously Bob Matthews wrote:

I am going to do away with the 'Thackery' washers on the inside of the rocker spindles and use shims instead on my 99.

I have never liked thackery washers as they cause unnecessary friction on the rocker arm and are quite a primitive way of doing things - although, they are foolproof to fit.

My question is to anyone that knows, how much side clearance to use? I was thinking of 0.002" - 0.003" and reasoned that the head will expand more than the rocker when hot and therefore the clearance will increase. If anyone knows different, please let me know.

Hello the Thackery washers are there for a proposeand that to keep the rocker arm to one side and in its place, and do not have any friction on the rocker arm or spindles the Thackerywashers fit nearest the middle of the cylinder head space, So not a good idea to remove them all together So See RGM motor and ask Rodger's advise they do have sets of new ones, and you need to check you have oil going into the rocker spindles from the return side, hope you get thing sorted, yours anna j

Bob

I quite like the idea and think you are on about something here.

I have done this on in the past and have experienced no problems whatsoever.

In place of the thackery washer I made bronze washers. Be sure to use steel shims against aluminium !

Clearance may be down to zero as long as the rockers move freely.

Regards

Arne

I'm with George on this. I did mine because I had access to engineering equipment that allowed me to measure the gaps. I wouldn't have spent £10 doing it though. the side friction is negligible.

hello well, as you may know, I was once a marine engineer but that was some time ago and every engine I have seen or rebuilt has some form of Thackery spring washers but in our days most modern forms of engine do not with there 4 valves per cylinder and Doubleoverhead camshafts and oil pressurised bucket over the valve springs, but at the end of the day its all up to the individual that owns the motorcycle as members we can only advise, but do make sure thisdoes not shove the valve out of line, or to one side as it will make the valve guide to break up and maybe distort the cylinder head in this area,

yours anna J dixon

Dear Anna

If you read the thread carefully, you will find that it is not a question of

doing away with the "thackary" function !

It is replacing it with a (more) precise distance washer...

Bob

This is quite easy to sort out if you make up a test arbor to use instead of the rocker spindle when you do the actual fitting.

Regards

Arne