The importance of polishing valves!

Question: how did you recognize it? Sound, smoke, you are used to disassemble the engine every 25k miles or whatever?
 
It's just shy of 40 years old and is having a complete rebuild, cleaning up the valves showed this little nasty up, it is lucky that it didn't let go before and ruin my day. The Inlets, although not cracked, are pretty grim, (the thing stood for 13 years before the bloke I bought it off started using it, I bought it in 2000 and it has lain idle for 15 years, time to to bits the old clunker and spend a bit of cash on it) so I will replace all six while it is in bits.
 
No problem Thomas. 😁
I will clean up the others tomorrow and see what they look like with all of the carbon removed, they are quite pitted on the combustion chamber faces though, so I might just talk nicely to my wallet and replace them all anyway. Anyone know the best place in the UK? Keith Nairn? or is it feasible to match and get them from a supplier of valves for the motor industry in general. Any advice well appreciated. 😊
 
A repair shop can recut the sealing surfaces. That might save you some money.
Like Thomas mentioned the other side is uninteresting.
And there might be work to be done, anyway. Like seat recutting etc.
 
Refacing is fine as long as you still have a reasonable width where the seat meets the outer edge. Inlets will often be concave and once refaced are too thin.
 
replacement valves for Laverda's are manufactured by G&S valves in Godalming, they have most details, maybe not all, and the type in your engine can be identified by the valve head size, I just phoned them and these are only made to special order (Laverda types) and if put in motion now, they would be manufactured around October, in practice then, you have to find someone with them in stock, Keith Nairn may well have them, (hope he has) more likely to be non UK
CLEM
 
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