Forum

[Norm]

Rebore, new pistons,valves,springs guides heads done by our headman who does all our heads, put it together , kicking it over with the plugs out and I am getting a very noticible click as each exhause valve shuts. I have looked and kicked, tipped oil all around the rocker gear,noise is terrible if I start it. Run out of ideas and just pulled the heads off again to take back to the headman to check. Any thoughts?

[another Allan]

Sticking rocker? Do they have Thackeray washers fitted on the rocker spindles? These can sometimes make a noise if the bearing surface in the head or on the side of the rocker has any damage. Sticking cam follower? Broken valve spring?

[Norm]

Hi Alan, it was fine before I pulled it down a few weeks ago to get it rebored and the heads done up. I have pulled the heads off again, can't find anything that was causing any noise, I held down on the pushrods as I kicked it over to see if anything was going on with the cams but that is all as quite as a mouse. It has to be something to do with the valve springs I think but both exhaust valves as they shut is a mystery so broken spring is out of the question apart from the fact that they are new

[Norm]

And besides I want this Inter out of my shed because it has been here for probably 3 years and now that his wife knows about it there is no reason for it to stay but I think it is suffering shedaphobia or the fear of leaving my shed

[Bullet Whisperer]

Hi Norm, is there any way that the exhaust valves could be just clipping the new, oversize pistons? Failing that, is the timing chain tight enough, or are the cam sprockets loose on the camshafts - I know you say you put thumb pressure on the pushrods, but valve spring pressure will be greater, even with the valve nearly shut. Do you have a copper head gasket clipping an oversize piston [disregard this if your barrels have spigots, but I have had that one before]
Cheers, Paul.

[Norm]

Hi Paul, timing chain is fine and I realise thum pressure isn't nearly up to valve springs but I am clutching at straws. This has cross rings and I was a little surprised that the piston was stopping probably 2mm below the cross rings.If anything the top of gudgeon to top of piston on the new pistons is about 1mm shorter. No sign of valves or anything touching. I'm leaning towards the valve springs binding up against each other and the click is as they release. Best I can come up with at the moment. As the click is as the exhaust valves actually shut, the piston is nowhere near the valves at that time.

[Norm]

Ok still no answer so I'm thinking of removing the inner springs, these days there is little chance of these motors suffering from valve bounce. Any thoughts on this?

[Bullet Whisperer]

Hi Norm - another stab at it, then - are the pushrods fitted the right way up, both ends are slightly different after all. Just a thought? Cheers, Paul.

[Norm]

Hi Paul pushrods the right way up as per the book

[Mark M]

Norm, there was a recent similar problem discussed on the Inter forum. Turned out the problem was wrong size Cross rings moving in the bores. Apparently not the cause here! However, the rockers are very susceptible to sideways movement and therefore noise. Some members have experimented with making solid thrust washers to replace the Thackeray washer on each spindle taking the opportunity to centralise the tappet adjuster on the valve stem. At the same time, you can fit the mushroom head tappet adjusters as fitted to late Triumph Tridents and BSA Twins (make sure they are CEI thread!) which run quieter and greatly reduce need for adjustment.
REgards, Mark