125-200cc Which Cylinder for 165 kit ?

Hello All !! I'm looking at going the 165 route. My question is what cylinder to use. I have noticed that there is different cylinders listed for certain years & models. What are the differences between them. Is one type more of a stand out than others, pros/cons ? I have access to a 08 WR125 cylinder assy w/head & power valves. Will this one be ok? Any advise is greatly appreciated and thanks in advance.

That one will be great. The older style like that tends to be a bit better on the bottom. They all work well from '98 to 2013 but the older style is just a bit more robust on the bottom than the newer style. I attribute this mostly to smaller but more transfers. This generates more velocity at lower rpms. The newer style probably has a bit of an advantage at peak rpms. The differences are slight though. The biggest issue with the older style is getting power valves. The old style are hard to come by and very spendy to buy new.

Thanks for the advice Wally !! I was hoping you would guide me in the right direction. Also how do I tell between the different year cylinders are there any marking to look out for?

The old ones have more transfer ports. seven? - new ones 5

Wally, I don't see a link in your profile to your shop info? Do you have a website detailing specifics on your engine services?

Try the Motorsportz website - Kelly handles the retail side for him