KR-1S.co.uk Forum

hi ya ive blown up my kr1s on a dyno but found out i have a 300cc convershon on it but now i need pistons the only problem is the pistons in it are 60.5 mil wide thay are the pistons from a yamaha vr 150 and thay are 1,5 mil over size can anyone tell me where i can get them or if there is any other pistons i can use stan stevens pistons are 61 mil wide so can anyone help thanks

This is the first time I've heard of anyone useing an off-the-shelf piston for a KR 300cc conversion.
How did you identify them as being from a VR150?
I'm sure there will be a few people looking for them now, as no-one has been able to work what pistons Stan Stephens uses (current thought has been that theyre custom).
Do you know if the combustion chamber has been machined (or anything else for that matter) to accomodate these pistons. Also, are you running and O-ring or a head gasket?
Cheers and good luck, Scott.

i know that the pistons are from a vr 150 due to the code 2jk cast on the piston and its marked 1.50 on the top of the piston and the casting looks like a yamaha cast. It runs a head gasket and the heads have been machined to match the barels and it looks like the porting has been changed as well but i did,nt do it so this is just what it looks like

www.energi-uk.com/energiuk/motorcycle.htm - 79k
Don't know the quality ????. But they list them. Alan.