cheers guys mg the hole was bigger on the inside but no damage to anything else valvers are good heads good boars still got hone marks i think i just got un lucky with these pistons
ive been serching and i think ill go jp 9:1
on a positive note this is all part of owning the bsa its great to ride and working on it is as much fun
thanks all for your imput much apreaciate it
I appreciate some people like JP's but I had nothing but trouble with them on my norton atlas, kept seizing, I went through several pairs of and heard a lot of other similar stories. Won't ever use them again! my preference would be some wiseco's from cake street and I pick up low mileage or new 8 or 9 to 1 NOS when ever I see them at a fair price. I'm running genuine BSA pistons in the road rocket, they are lovely and light.
ps I have a set of 10.5:1 just like those and will put them in a methanol motor...