Valve Clearances – Camel.

[Butch]

I’ve just had my recently purchased Camel up on the table for a first time look over before buying some service items. Popped the top to check the valves and also the RH cover for the belt code on the upper pulley. The valves seem tiny even by V50 standards (which I’m more used to). Checked the valve clearances whilst I was in there and nipped up a couple of them by maybe a thou. But here’s the thing – the lock nuts are all pristine looking 10 mm AF, but three of the adjusters are a 4 mm AF square and the fourth one is a tiny socket head in the end; like a grub screw.

The bike seems to be genuine low mileage, and I have lots of receipts for loads of other stuff – but nothing for engine bits. Anyone got any thoughts on what might have happened here?

Thanks

[Steve Brown]

The odd one out must be a replacement after some distant past repair. If the profile of the contact end is ok then fine, but they are not rare parts and it would be nice to have four the same I think? Anyone who has been messing with Morinis for a while will likely have some lying around. So will NLM.

[Butch]

To be honest, I’m not too worried about differences within; assuming that any aspects of different weights will not be an issue here.

More concerned as to what might have led to this swap out in the first place. I’m presuming there is not a known weak point in this area that might lead to this.
So otherwise, has there been some catastrophic failure? Or has the bikes done a bunch more miles than the odo suggests.

It’s the joys and woe of mechanical archaeology at work really.

[George 350]

Hi Butch,

The only thing that immediately springs to mind is a cam belt failure, and that rocker's valve was the unlucky one that made contact with the piston. In itself not a reason to start paniking - the valves are inline with the piston, and the rockers are the bits that sacrifice themselves to prevent greater carnage. At least, that is my personal experience.
You CAN be the unlucky one where the valve bends a little and cracks the guide, but it is somewhat rare.
Are both valves at the same height in the head? If so, then the chances are that there is nothing to worry about.
Belts can and do die of old age as well as mileage.
Having said the above, if it is running well and isn't burning oil, then as you say, box it up and enjoy it.

George.

[72degrees]

I had an adjuster go loose once while 'racing' the original hill climber. Perhaps initially due to me not tightening the locknut properly. I tied re-setting it before the next run (with the locknut good and tight) but it went again and the thread appeared to be stripped/damaged. My solution was to buy a new rocker with adjuster, but perhaps someone has just put in a socket head grub screw, as the adjuster was toast but the thread in the arm was OK.

I don't think it is necessarily a sign of a catastrophic failure.

[Butch]

Thanks for responses. I’m not going to delve deeper for now anyway.

I’m expecting a new belt to be arriving for me to fit this weekend.

[Butch]

Hmmmm, slightly thickening plot on this one. I'm out in the garage putting in a new cam belt and doing other service items today. That 'odd' adjuster is on the front pot. Just noticed that the exhaust nut on there has suffered some minor butchery, that on the rear is still pristine. Head and barrel joints look clean enough from the outside though, but it's beginning to look like maybe someone has been in there before.