what engine does anyone recommend. I have the LRD adjustable pipe and silencer. Ported and polished cylinder, .060 over, Cool Head, Boyesen rad valve and spacer, 39mm Keihin. Uni Filter no lid.

Should i just bore it to .080 over?? or should i get a big bore kit from LRD. I have heard nothing but bad about CT and Trinity.

i usually race A or Pro class.

 

It sounds like you have all you'll need. The big bores are nice, but unless you like racing open class then they are not for you. Ported 250 cylinders are extremely fast and competitive even with the big bores because they rev faster. I personally don't think that too much is gained from the .080" bore unless you plan on using a different type of piston. That is what Sparks does, the YZ piston he uses starts at 68mm so that is why they bore it that far.

 

Are you asking about your top end only? Call around to LRD, Curtis Sparks, or I would suggest Rick Kirmil from www.macdizzy.com/. He knows a lot about R's and could answer all of your questions for you. Stick with a more reliable 270 style setup. Displacement isn't the key to everything, I watched a race this summer where Doug Gust beat a LT500(who usually wins A class around here) in the hole shot both motos. Of course he won both of them too.
ERIC

 

The thing with a 2 stroke is the porting. Get it right and it'll scream. I have a friend that got a resleeved 300 R and my 270 blows his doors off!
Check out MacDizzy.
Then, really think about what you want to do, where you want your power, etc. Then go from there.