Quote:
Originally Posted by Megadan
The only other unknown factor that needs to be accounted for is jug deck height. If you overbore a 125/150cc jug then it's no issue. The 200 and 250 jugs are taller.
Then you will also be tossing a different piston into the mix that could alter that spec as well, and if that different piston has a different crown height or dome height to the original it can also affect clearances on both the 125/150 jugs, and the bigger ones.
This may be your best option. It has the right 68mm sleeve bore size, is a 65.5mm bore and has a 15mm wrist pin.
https://www.aliexpress.us/item/32568...TQ5Ni42MC4wLjA.
Anything bigger than 65.5mm will be a CG250 sleeve diameter, which is 73mm and would require the case halves to be bored. If you try to bore any of the smaller jugs out to 67mm your skirt thickness at the sleeve would be .5mm, which is way too thin. |
Actually, I found a set that looks exactly like the one you just linked. Piston dome, crown exactly the same. Though it is a 67mm bore and 69 height. So skirt thinness wouldn’t be a problem I believe. I could also bore the case halves no worry about that.
Other than that. Do you recommend these roller valve arms sold on AliExpress? Are they better than the flat ones? And would an oil cooler be necessary on this build? If yes, oil pump upgrade needed?