Just joined forum and purchased this....

[mick43]

Hope not to bother you all too much with queries in near future 
Just had engine and gearbox re-build so fingers crossed for some trouble-free miles.
I did ask if cylinder head had been converted for unleaded - it hasn't - but owner said this wasn't necessary (but opinions did conflict - so I'll do some searching here...).

[bsa-bill]

Hi Mick43 and welcome
Nice tidy bike you have there
if you've got questions please ask away, without questions there would be no forum
As for the unleaded, best just keep an eye on the tappet clearance if there's an issue then the clearance will get less, don't think it's an issue at all with cast heads but shooting Stars and Rockets with their alloy heads might benefit from a lead substitute such as Castrol Valve Master Plus which also has an octane booster (helps limit pre-ignition too)

[pato08]

Hi Mick, and welcome, ask all the question you like, I print off all relivant questions and answers, and keep them in a nice little folder in my "man cave'.
We all learn from others mistakes, as you will never live long enough to make them all yourself.

Pato
Australia.

[Sparky]

This is actually a very relevant question for people who enjoy messing around with leaded gas era engines.  I am no expert, but it is my understanding that it is primarily the valve seat material that suffers from "recession" from the lack of lead in the fuel.  I don't really know if the original seats in alloy heads were more prone to this than the cast iron head seats, but the consequence would be an accelerated rate of decreasing tappet clearance as mentioned.  If you plan to run your bike fast and hard, I would definitely plan on replacing the seats, at least on the exhaust valves.  If it's just going to be used for a leisurely ride now and then, you could probably get by with the addition of a "lead substitute" to the fuel.  There are a number of such products available here in the states.

[duTch]

Hi Mick,
           As the others said -'ask Away', don't worry, I'll make you look good, it's all a big learn. I reckon it's those 'dumb' questions that are the smartest.

 Cheers dutch

[bsa-bill]

Hi Sparky and all
Was pretty sure I read somewhere that our cast heads were designed before lead was introduced to fuel therefore they were unleaded proof so to speak.
Well further investigation reveals lead was introduced to UK fuel in the 1920s (around the same time in US I think) so that blows that theory out of the water

[Rocket Racer]

Looks lovely in silver! very nice, wish my road bike was that tidy.
As for valve seats, sadly the poms were a bit cheapskate and fitted quite soft valve seats that will wear over time without lead or equivalent additives.
Mainly an issue with hard riding and bigger mileages, as previously mentioned, tappet checks will highlight. If you do get seat recession and dont check tappets worse case it is possible to burn a valve, but that assumes a no maintenance regime which is always a bad idea.
Enjoy

[duTch]

Sorry, but b-Bill as I read yours, I couldn't help wondering if that was when they also put the lead in ballons?? cheers

[bsa-bill]

Possibly balloons Dutch but more likely Zeplins (sorry to Plant that one in)
Now to get back on subject before E pins a note in - any news Mick43

[duTch]

Sorry Mick and Robert(bill) got side tracked and forgot this bit.
I asked my mate Kel, when I used his gear to cut my seats, about unleaded, and he said should be fine(alloy haed), and most exhaust valve are stainless anyway, at which I was surprised?? So yes, I'm keeping tabs on this one??
 Cheers

[mick43]

thanks all for advice/feedback..