Thanks for the answer.  
I have just bought the Cub (non running) and my trialfriends says that 199cc is not strong enough. Maybee i chould try it for one sesong  first. 
I have Doyer Bransden, R-cam and 7;1 piston and Kehein carburettor. I had not try it in sections yet. So far i have drive my TLR250. 
If I find it to weak I start with some later cases as Subira told me, but I like to do it myself as I have the machines.