if you want my opinion it would be as good as any bog standard engine out there,the cy are grand but its like comparing a honda bike to an aprillia.
or a nissan to a skoda...
i mean the thing about these engines they are pretty basic all of them,but you just cant rely on cy i think,there cylinder plating can and is softer than zenoah,the outer casings where you will be bolting on stuff sheer off easily...just a pain in the a**
if you want to know the truth,save the extra few quid and buy a zenoah(any cc) rock solid reliality and great power,in my opinion a 23cc zenoah would eat a 29cc cy,i have had both and its the truth.
the best of the bunch if you could and is prob the cheapest best performing of the bunch is the zenoah G260. excellent motor.
or the new four bolt zenoah G270 but that is a bit more $
save youself a lot of grief and stay clear of cy.
its easy to c y zenoah is the best lol