Running in?

[Nick]

When I bought my bike it had just been recommissioned and I was told it need running in.
I have now done 750 miles and am starting to take it over 4k revs.
My question is what  revs are normal for the engine? According to a Classic bike special on Silks they don't take too well to harsh treatment.

 Also what is the the red line?
My rev counter is not standard and shows 7k which seems high?

[hendred]

Max power is quoted at 6,000 rpm so don't see any reason to exceed this.  My Silk feels very "busy" much over 4000 rpm but this may be me as I am more use to 4 stroke singles! The porting on mine gives a definite surge in power  about 4500 rpm which is slightly variable with ignition timing.  I rarely go much over 5000 rpm. I have a 17 tooth gearbox sprocket fitted which results in 4000 rpm giving a speed of just over 60mph.  The small sprocket helps with pulling away from standstill but not very relaxed cruising.  In my opinion I'm not sure why anyone would want to thrash a 40 plus year old bike with limited spares availability - there are other bikes with good spares availabilty for that.  I just enjoy the light weight, good handling and riding something a bit special but not especially fast.

[Smokey_Paul]

Which do you have Nick and what was rebuilt?

General running is as per Hendred says generally Silks seem happy around 60mph

4000rpm seems right now upto 1000 miles good service and off you go.

[Nick]

Mine is a mk2 engine no 83 looks like frame 81
I am not sure what was done to the. bike before I bought it. It looks to have sat in someones garage for years.
In 2018 the last owner died and it was recommissioned and sold through H & H auctions (don't trust anything they say!!) I was lucky it has always been a great starter just needed a few bits to improve its running and ridding. I have spent the last 3 years saying "I will sort that then sell it. Then when I have sorted something and then ridden it, I love it and want to improve it a bit more!!
4 speeds and high grearing mean its not really suited to the West Yorkshire hills. But I did the Northern section
Scott 1928 re-run on it and what a lovely day!
All the other 6 Scott owners were great and I won the trophy for best presented bike!! They do this every year and its worth doing. I felt like I was in a vintage movie ridding with a 1929 and 1930 Scotts and was amazed how capable they were.

[Smokey_Paul]

All sounds fine just keep on top of the servicing and plug swaps and use a good quality 2 stroke I wouldn't worry. Some have been toured 2 up around Scotland with no issues just look after it and all will be fine.
By no. 83 and MK2 most of the issues had been sorted and the bike made reliable but may be worth looking at a modern regulator if you haven't upgraded already for more reliable 12v.
The Silk is no more fragile than any 40 year old Classic exactly as Hendred put it, mostly rumoured by people who have never had one!